Instruction Manual Model 9120, 9121, 9122 & 9123 SINGLE OUTPUT PROGRAMMABLE DC POWER SUPPLY
Table of contents General Information ……………………………………………. Features …………………………………………………..……… 5 7 Local Mode Operation ………………….……………………….. Front Panel Description ……………………………………………. Memory Key ………………… ……………………………………. Storing States in Front Panel Mode ………………………………… Recall Key …………………………………………………………. Recalling States in Front Panel Mode ……………………………… Limit Key ………………………………………………………….. Modes of Operation ……………………………………………….. Constant Current Operation ………………………………………...
Table of contents Remote Interface ……………………………………..………….. RS-232 Interface …………………………………………………... 55 55 GPIB / 488 Interface ………………………………………………. Functional Description of GPIB / 488 Interface ………………….. IEEE 488 Addressing ……………………………………………... Bus Description ……………………………………………………. Sending Commands Over GPIB Remote Interface ……………….. Serial Poll Procedure ……………………………………………… Interrogative Commands Over GPIB Interface …………………… 56 57 58 59 61 62 62 Commands Sent Over Remote Interface …………………………..
Table of contents Technical Specifications ……………………………………….… Supplemental Characteristics ……………………………………… Programming Ranges ………………………………………………. Reset Va lues ……………………………………… ………………... Interface Cable ……………………………………………………… 105 110 112 113 114 Warranty Information ……………………………………….… Service Information ………………………………………….
General Information Single output programmable DC power supplies. Output voltage is: 0 to 30.0 V for Model 9120 0 to 20.0 V for Model 9121 0 to 60.0 V for Model 9122 0 to 30.0 V for Model 9123 Output current is: 0 to 3.00 A for Model 9120 0 to 5.00 A for Model 9121 0 to 2.50 A for Model 9122 0 to 5.00 A for Model 9123 The power supply can be locally or remote controlled.
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Features • Constant Voltage / Constant Current modes of operation This power supply can operate in either constant voltage or constant current modes. The passing from one mode of operation to another is automatic. The active mode of operation is indicated using two indicators: CV – constant voltage mo de of operation CC – constant current mode of operation • Overvoltage protection Overvoltage protection circuit can be locally or remote activated. When it is active, ovp indicator is displayed.
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Local mode operation Front Panel Description Memory Key Note: Memory location 00 is the power_up state. When the unit is powered up, the power supply will set itself to the settings stored in location 00. Note: If you press the Recall button while turning the power on, the power supply will power up using memory location 01 parameters. This button is used to store power supply’s current operating state in nonvolatile memory. Using this function all operating parameters are saved so they can be recalled.
Options are selected by pressing Memory key when the desired option is displayed. Memory Menu Overview Store State Store State option will store the current operating state without setting a name for this state. By pressing Memory key, state number and state name (if you set one) are displayed in ascending order by turning the knob. In this menu, Exit option is available, too. In this case, you leave the store operation mode, without changing anything.
In this menu Exit option is available, too. In this case, you leave the store operation mode, without changing the name for any state. No Change message will be displayed and the power supply returns to the previous state (the state before entering Memory menu). Important note! Store State option will store the parameters of current operation state in the selected location and will not set a name for the stored state. NameState option will set a name for the selected state.
Storing States in Front Panel Mode To store an operating state in front panel mode you must follow the steps described bellow: 1. Set the power supply in the desired operating state Stored parameters are: voltage limit, voltage step, overvoltage protection level, state of overvoltage protection circuit, current limit, current step, voltage trigger value, current trigger value, trigger delay value, trigger source, stored state name, state of display, output state.
The saving action is realized by pressing Memory key. After that, Done message will be displayed and the power supply returns to normal mode. 4. Select Name State option In order to select this option , Memory key must be pressed again. NameState option allows you to set a name for the selected state. The saving action is realized by pressing Memory key. After that, Done message will be displayed. Done Important note! The power supply allows 100 states to be stored.
Recall Key This key is used to recall an operating state from the storage locations in nonvolatile memory. You can recall any operating state from 100 different operating states stored in the non-volatile memory. The recalled state becomes the current operating state. By pressing Recall key, you enter in Recall menu. By turning the knob, following options will be displayed: 00: power_up 01: 02: Test_mode etc.
Exit Exit option allows you to leave the Recall menu, without changing anything. No Change message will be displayed and the power supply returns to the previous state (the state before entering Recall menu). Reset Reset option allows you to reset the power supply without switching off (for more information, please refer to Reset Values section). 00: power_up After power up, the power supply recalls state 0.
Recalling States in Front Panel Mode To recall an operating state in front panel mode, you must follow the steps described bellow: 1. Enter the Recall menu By pressing Recall key, you enter the Recall menu. By turning the knob, following options are displayed: 01: State 1 02: Test_mode etc. (all 100 operating states are displayed) Exit Reset 2.
Limit Ke y The power supply works in 2 modes: Ø Limit mode Ø Normal mode In limit mode limit values of voltage and current are displayed. These are the programmed values (from the front panel or over the remote interface). Limit key is used to get the power supply to limit mode. In this mode, lmt indicator and limit values for voltage and current will be displayed. In limit mode, limit values can be adjusted by turning the knob.
Modes of Operation Depending on the application, the power supply can be used as a constant current source or as a constant voltage source. In order to understand constant current and constant voltage operation, a numeric example will be used. Uout R Let’s consider a resistor connected to the output terminals of the power supply (R resistor). Limit (programmed) values are: Ulim =5V Ilim =2A Uout and Iout are the voltage and current terminals of the power supply.
When the resistor’s value decreases so the output current value becomes equal to the current limit value, power supply will go to constant current operation (see third row of the table). If the resistor value is R = 1 Ù, for Uout = 5V, using Ohm’s law the output current is 5A. But this value is greater than current limit value, so the power supply limits the output current to the limit programmed value. That is why in the third row of the table Iout = 2 A. In this case, Uout is changed, too.
Constant Current Operation In constant current operation, current values in limit mode and normal mode are the same, but voltage values are not. To set the power supply in constant current operation, you must follow the steps described bellow: 1. Select the limit values for voltage and current parameters (Ulim and Ilim ), depending on the application 2. Calculate resistor’s value Rload.
8. Enable the output of the power supply By pressing On / Off key, you enable the output. Power supply goes to normal mode operation and CC indicator will be displayed. In this case constant current operation is active. If CV indicator will be displayed, you must set a higher value for voltage limit. Important note! By turning the knob, voltage and current limit values can be adjusted. The adjustion of the voltage limit value can be seen only in limit mode.
Constant Voltage Operation In constant voltage operation, voltage values in limit mode and normal mode are the same, but current values are not To set the power supply in constant voltage operation, you must follow the steps described bellow: 1. Select the limit values for voltage and current parameters (Ulim and Ilim ), depending on the application 2. Calculate resistor’s value Rload. Using Ohm’s law, calculate the resistor’s value that allows the power supply to go in constant current mode of operation.
8. Enable the output of the power supply By pressing On / Off key, you enable the output. Power supply goes to normal mode operation and CV indicator will be displayed. In this case constant voltage operation is active. If CC indicator will be displayed, you must set a higher value for current limit. Important note! By turning the knob, voltage and current limit values can be adjusted. The adjustion of the current limit value can be seen only in limit mode.
On / Off Ke y On / Off key is used to enable / disable the output of the power supply from the front panel. By pressing On / Off key, you alternate these two states: output on / output off. When the output is off, power supply displays: Output off The indicators according to power supply’s state will also be displayed (e.g.: ovp, err indicators). When output off, output voltage is 0 V. So this command permits a zero output voltage without switching off the power supply.
Remote / Local Key This key has a double function, depending on the state of the power supply (remote mode or local mode). Local Mode Function While in local mode of operation, Remote / Local key has a double function, depending on the state of the power supply.
By turning the knob, following options will be displayed: RS - 232 GPIB / 488 By pressing Remote / Local key once again, the displayed interface is selected and the specific parameters can be set (for RS – 232 interface, baud rate and parity will be set, for GPIB interface GPIB address of the power supply will be set). The parameter values can be changed by turning the knob. When desired value for the parameter is displayed, Remote / Local key must be pressed.
RS-232 Configuration Available settings for RS-232 interface: ♦ Baud rate: 1200, 2400, 4800, 9600 (factory setting: 9600) ♦ Parity and data bits: None – 8 data bits (factory setting) Odd – 7 data bits Even – 7 data bits ♦ Number of start bits: 1 bit (cannot be changed) ♦ Number of stop bits: 1 bit (cannot be changed) Set RS – 232 remote interface parameters 1. Select RS – 232 interface Press Remote / Local key. If “GPIB / 488” is displayed, turn the knob until “RS-232” will be displayed.
GPIB / 488 Configuration Available setting for GPIB / 488 interface is address of the power supply. An IEEE 488 address can take values from 0 to 30. GPIB address is kept in a non-volatile memory, so when powered on, the last selected address is active. When supplied from the factory, power supply’s GPIB address is 5. Set GPIB remote interface parameters 1. Select GPIB / 488 interface Press Remote / Local key. If “RS-232” is displayed, turn the knob until “GPIB / 488” will be displayed.
Remote Mode and Indicators When RS-232 interface is selected, SYSTem:REMote command must be the first sent command. Otherwise, if another command is sent first, Power supply in local mode message will be sent to PC. While in remote interface mode of operation (after sending SYSTem:REMote command), rmt indicator will be displayed. In this case, all front panel keys are disabled, except Remote / Local key, which is active.
Errors / Calibrate Key This key has a double function: errors related in normal mode (see this section) and calibration related in calibration mode (see calibration section). There are 2 types of errors: user defined errors and errors defined by SCPI 1999 standard. Every time an error is generated, a beep will be generated by the power supply and err indicator will be displayed. Generated errors are saved in an error queue, in FIFO (first in – first out) order.
After several seconds the power supply will go back to normal mode. The err indicator will not be displayed anymore. If there are no errors in the queue and you select Errors option in order to view the errors, the power supply will display: No Errors And then it will return to normal mode. There are 3 ways of erasing the error queue: ♦ By turning off and then turning on the power supply ♦ By pressing Errors / Calibrate key after errors are displayed, in local mode ♦ By reading errors, in remote operation.
After the first scrolling of the calibration message, < or > keys must be pressed in order to scroll the message again. Exit Exit option allows you to leave this menu, without changing anything. Exiting message will be displayed and the power supply returns to the previous state (the state before entering this menu). Important note! If you enter in the Errors / Calibrate menu and no action takes place for approx. 20 seconds, the power supply leaves this menu.
Calibration Overview Calibration is a procedure that ensures that the power supply will work properly, with parameters specified within Technical Specification section.
Unsecure Procedure for Calibration To unsecure the power supply, the next steps bust be followed: 1. Turn on the power supply in calibrating mode To enter calibrating mode, you must turn on the power supply while pressing Errors / Calibrate key. You release the key after the long beep. After that, the power supply will display: Calibrating Mode Secured if the power supply is secured (if the power supply has a security code set). If this message is displayed, go to step 2.
From this moment you can proceed with calibration (see Calibration procedure section) or you can go back to normal mode operation. From now on, the power supply remains unsecured until you set a new secure code. If the security code you entered is not correct, power supply will display: Security code: invalid for 1 second. 703 error (Invalid secure code) and a short beep will be generated. You can see the error in normal mode operation (by pressing Local key).
it is finished) does not change anything concerning the secure state of the power supply (secured or unsecured). After you changed the security code or unsecured the power supply, you can go back to normal mode by pressing Local key. (You can come back to calibrating mode only by turning off the power supply and starting it in calibrating mode). But once you started the calibration procedure, it is recommended to finish it and to go back to normal mode by turning off and on the power supply.
Hardware Unsecure Procedure for Calibration This procedure may be used to unsecure the power supply if you forgot the security code. To unsecure the power supply without using the security code, follow the next steps: 1. 2. Turn off the power supply. Disconnect the power cord and all loads connected to the power supply. Remove power supply’s cover. Set J6 jumper for hardware unsecuring mode. J5 J6 J5 J6 Normal Hardware unsecuring unsecuring 3. 4. Connect the power cord to the power supply.
The power supply remains unsecured until you enter a new security code. Important note! Even if you are in calibrating mode, you cannot set a security code as long as the J6 jumper is in hardware unsecuring position. 5. Set J6 jumper for normal unsecuring mode. Important note! If you turn on the power supply in either normal mode or calibrating mode and J6 jumper is in hardware unsecuring position, error 701 (Calibration security disabled by jumper) will be generated. 6.
Calibration Procedure Before initiating the calibration procedure, the following conditions must be assured: § disconnect any loads connected to the power supply and turn it on § let the power supply turned on for 1 hour, with no loads connected before you start the calibration procedure § calibration ambient temperature must be 25 0 C § ambient relative humidity must be less then 80%. On calibration procedure there are three parameters that must be calibrated: voltage, OVP and current.
Voltage Calibration Procedure After you unsecured the power supply and you pressed Calibrate key, you entered calibrate mode. Volt Zero Scale Calibration 1. Select Volt Zero Scale calibration procedure In order to start voltage calibration procedure, you must select Volt Zero Scale option. The power supply will display: Calibrating Mode Volt Zero Scale You select this option by pressing Calibrate key. The power supply will display: Volt Zero Scale DAC:1999 2.
Volt Full Gain Calibration 1. Select Volt Full Gain calibration procedure In order to finish voltage calibration procedure, you must select Volt Full Gain option. The power supply will display: Calibrating Mode Volt Full Gain You select this option by pressing Calibrate key. The power supply will display: Volt Full Gain DAC:31470 2. Initiate DAC calibration procedure Connect a digital voltmeter to the output terminals of the power supply.
OVP Calibration While performing this calibration procedure, the power supply must have no loads connected to the output terminals. 1. Select OVP calibration procedure In order to initiate OVP calibration procedure, you must select OVP option. The power supply will display: Calibrating Mode OVP You select this option by pressing Calibrate key. The power supply will display: Calibrating OVP Please wait… Important note! This calibration procedure will take several minutes.
Current Calibration Procedure Current calibration procedure must be permormed after Voltage calibration procedure. Current Zero Scale Calibration While performing this calibration procedure, the power supply must have no loads connected to the output terminals. 1. Select Curr Zero Scale calibration procedure In order to start current calibration procedure, you must select Curr Zero Scale option. The power supply will display: Calibrating Mode Curr Zero Scale 2.
Current Full Gain Calibration 1. Select Curr Full Gain calibration procedure In order to finish current calibration procedure, you must select Curr Full Gain option. The power supply will display: Calibrating Mode Curr Full Gain You select this option by pressing Calibrate key. The power supply will display: Curr Full Gain Connect Ammeter 2.
3. Initiate ADC calibration procedure Press Calibrate key. This will initiate ADC calibration procedure. The power supply will display: Curr Full Gain ADC Calibrating After ADC calibration, power supply will return to Calibrate menu. In this moment, the calibration procedure is finished. By presing Local key, the power supply will return to local mode.
OVP / Secure Key This key has a double function: OVP settings in normal mode operation and secure key in calibration mode operation (for the latter see Calibration section). In this section OVP functions will be described. OVP circuit prevents the output voltage from rising above a programmed voltage value. So the load connected to the output terminals is protected of overvoltage situations.
By turning the knob, following options are displayed: OVP On OVP Clear OVP Off Options are selected by pressing OVP / Secure key when the desired option is displayed. OVP On OVP On option enables overvoltage protection circuit. OVP trip level is the level value you programmed on Level option (after you first pressed OVP / Secure key). If you want to keep the previously programmed trip level, you simply press OVP / Secure key, without changing anything.
supply (see the table above). In this case, the programmed OVP trip level, shown in OVP menu does not change! OVP Clear OVP Clear option is used to clear to OVP condition (for more information about how you get back to normal mode after OVP level was tripped, please refer to the next section). After you select the desired option, a message will be displayed. If you didn’t change anything of the previous set parameters, the power supply will display No Change message.
Programming OVP Circuit in Front Panel Mode If you want to program an OVP trip level and to enable the overvoltage protection circuit using front panel keys, follow the next steps: 1. Turn on the power supply When you turn on the power supply, the overvoltage protection circuit is enabled and OVP trip level is set to maximum available value for OVP parameter, depending on the model of the power supply (see table in the prevous section). 2.
Clearing Overvoltage Condition There are three ways of clearing the OVP condition: Ø By increasing OVP trip level and clearing the OVP condition Ø By decreasing the output voltage and clearing the OVP condition Ø By disabling OVP circuit and clearing the OVP condition Attention! The latter solution disables the OVP circuit, but the first and the second don’t! In this section we will describe the steps you must follow to clear the OVP condition in all three cases.
Clear OVP Condition by Increasing OVP Trip Level 1. Enter the OVP menu By pressing OVP / Secure key, you enter the OVP menu. 2. Adjust OVP trip level When you enter OVP menu, OVP trip level is displayed. Here, you set OVP trip level to a level higher than the programmed voltage value (Ulim ). 3. Clear OVP condition After you set the OVP trip level, you press OVP / Secure key. Here, OVP On, OVP Off, OVP Clear options are available. Select OVP Clear option by turning the knob.
Clear OVP Condition by Decreasing the Output Voltage 1. Decrease the output voltage level bellow OVP trip level Press Limit key and enter limit mode. Limit values of voltage and current will be displayed. ovp and lmt indicators will also be displayed. Adjust for output voltage limit to a lower value than the OVP trip level. Press Limit key to exit limit mode. 2. Enter OVP menu and clear OVP condition Here you check that the OVP trip level is greater than the output voltage limit you set.
Clear OVP Condition by Disabling OVP Circuit 1. Disable OVP circuit By pressing OVP / Secure key, you enter OVP menu. Here you disable OVP circuit by turning the knob and selecting OVP Off option. OVP Off It doesn’t matter if you change or not OVP trip level as long as you disable the OVP circuit. But you must be careful to set it to the right value before you enable OVP circuit next time.
Rear Panel Description On the rear panel of the power supply there are: § RS-232 interface connector § AC inlet § Power-line fuse-holder assembly § Rear output terminals. +s + - -s The sensing terminals (+s and -s) are connected to the output terminals of the power supply by jumpers. For the power supply to work properly, the jumpers must be kept in that position.
Remote Interface For remote communication, there are two available interfaces: GPIB / 488 interface and RS-232 interface. The selected interface and the coresponding settings are saved in a non-volatile memory and does not change after the power supply is turned off or after a *RST command. Only one interface can be active at a time. When the power supply is delivered, GPIB / 488 interface is selected.
GPIB / 488 Interface GPIB / 488 interface availability for different models: RS-232 GPIB / 488 9120 Standard Optional 9121 Standard Optional 9122 Standard Optional 9123 Standard Standard GPIB (General Purpose Interface Bus) interface is also known as IEEE 488. The original 488.1 specification defines the mechanical and electrical characteristics of the interface and its fundamental protocols. The 488.
Functional Description of GPIB Interface Devices from the interface are classified into 3 types: Listener: a device capable of receiving data over the interface when addressed to listen by the Active Controller. There can be up to 14 Listeners on the bus at one time. Usually the Active Controller will be the Talker, while a single device is the Listener. But it is also possible that multiple Listeners will be assigned. In this case, all of them will execute the received commands.
IEEE 488 Addressing An IEEE 488 address can take values from 0 to 30. When supplied from the factory, power supply’s GPIB address is 5. An IEEE 488 device has a Listen address and a Talk address. Listen address and Talk address bytes are different. Listen address is defined by adding decimal value of 32 to the address. Talk address is defined by adding decimal value of 64 to the address. Decimal value of 31 is a special address value. Listen address byte has the value of 63 decimal (31 + 32 = 63 decimal).
Bus Description The interface signal lines are organized into three functional groups: Data lines (8 lines) Handshake lines (3 lines) General bus management lines (5 lines) The bus signal lines use low true logic protocol. Data lines: allow transfer of one byte at a time. Bytes are transferred over the interface in a byte-serial, bit-parallel manner. DIO1 represents least significant bit of the byte, while DIO8 represent most significant bit of the byte transffered over the interface.
General bus management lines: - ATN, IFC, REN, SRQ, EOI and they are used by the Active Controller or System Controller to manage GPIB interface SRQ (Service Request): This line is used by any device from the bus. when is set true (low), the device notifies the Controller that it needs servicing a request. Controller will perform a Serial Poll or a Parallel Poll in order to determine which device requested a service and why. IFC (Interface Clear): This line is used only by the Controller.
- when ATN line is false (high), the bus is in data mode and data bytes are transferred over the interface. These bytes may be SCPI commands sent by the addressed Talker to the addressed Listeners. or a response sent by a previously interrogated Listener (eg: response to an interogative command). The interrogated device must be addressed as a Talker in order to be able to transmit the response. Only addressed Listener (s) will acknowledge them.
Serial Poll Procedure When serial poll procedure is initiated, a device is addressed to talk and Active Controller sends Serial Poll Enable command (ATN line is low, because addresses and GPIB command bytes are transferred over the interface). The addressed device sends back to Active Controller a Status Byte (ATN line is high, because data bytes are transferred over the interface).
Commands Sent Over Remote Interface There are several types of commands that can be sent over the remote interface, in order to control the power supply: § SCPI (Standard Commands for Programmable Instruments) commands these commands are defined in the Power Supply Instrument Classes of the 1999 SCPI standard. a complete description of synthax and functionality is contained in the 1999 SCPI standard. these commands can be sent over RS-232 interface and GPIB / 488 interface.
Introduction to SCPI Language Here are some conventions used in SCPI standard: ♦ ♦ ♦ A command consists of a command keyword (command name) and a parameter (it may be optional or not) Lower case and upper case letters are considered equivalent Letter case is used to differentiate between the accepted short form (the uppercase characters) and the long form (the whole keyword) ♦ Square brackets ( [ ] ) are used to enclose: ♦ a keyword that is optional when programming the command ♦ one or more parameters t
SCPI Command Terminators A command string sent to the power supply must terminate with a new line character (ASCII decimal code of 10) or a a carriage return character (ASCII decimal code of 13). For multiple commands sent in a single message, command separator is semicolon character (03b h). Important note! The power supply will go to remote mode of operation (it can accept commands over RS-232 interface) if SYSTem:REMote command is sent.
SCPI Commands DISPLAY Subsystem :DISPlay [:WINDow][:STATe ] {OFF|ON} [:WINDow][:STATe ]? [:WINDow]:TEXT[:DATA] [:WINDow]:TEXT[:DATA]? [:WINDow]:TEXT:CLEar MEASure Subsystem :MEASure :CURRent[:DC]? [:VOLTage][:DC]? MEMory Subsystem MEMory:STATe :NAME , :NAME? OUTPut Subsystem :OUTPut [:STATe] {OFF|ON} [:STATe]? SOURce Subsystem [:SOURce] :CURRent[:LEVel][:IMMediate][:AMPLitude] {|MIN|MAX|UP|DOWN} :CURRent[:LEVel][:IMMediate][:AMPLitud
STATus Subsystem STATus:QUEStionable [:EVENt]? :ENABle :ENABle? SYSTem Subsystem :SYSTem :BEEPer[:IMMediate] :COMMunicate:GPIB:RDEVice:ADDRess :COMMunicate:GPIB:RDEVice:ADDRess? :ERRor? :INTerface GPIB|RS232 :VERSion? TRIGger Subsystem INITiate[:IMMediate] TRIGger[:SEQuence]:DELay {|MIN|MAX} TRIGger[:SEQuence]:DELay? [MIN|MAX] TRIGger[:SEQuence]:SOURce {BUS|IMM} TRIGger[:SEQuence]:SOURce? *TRG Non-SCPI commands SET {|DEF|MIN|MAX}[,|DEF|MIN|MAX] SET
IEEE 488.
SCPI commands overview DISPlay Subsystem This subsystem controls the presentation of textual information and measurement data. :DISPlay[:WINDow][:STATe] {0|1|OFF|ON} This command turns power supply’s display off and on. When the display is off, only indicators are displayed. When the display is on, power supply is in nomal mode (measured or programmed values of voltage and current are displayed.). You can replace off|on parameters with 0|1 numeric values.
MEASure Subsystem This subsystem contains commands that allow you to measure the current and voltage to the output terminals of the power supply. :MEASure:CURRent[:DC]? This command queris the current measured to the output terminals of the power supply. :MEASure[:VOLTage][:DC]? This command queries the voltage measured to the output terminals of the power supply. Important note! VOLT? Command returns previously programmed voltage level.
MEMory Subsystem This subsystem contains commands that manage power supply’s memory locations. MEMory:STATe:NAME , This command allows you to name a memory location. The numeric value parameter gives the number of the memory location that will be named. It can be between 0 and 99. The quoted string contains the name of the location. The name can be sent between simple or double quotes and it can have up to 10 characters.
OUTPut Subsystem This subsystem controls the output of the power supply. :OUTPut[:STATe] {0|1|OFF|ON} This command enables and disables the output of the power supply. You can replace off | on parameters with 0 | 1 numeric values. When output is enabled, the power supply will display voltage and current value measured on the output terminals of the power supply. When output is disabled, the power supply will display Output Off message and the indicators according to power supply’s state.
SOURce Subsystem According to SCPI standard, SOURce node is optional, so the devices which are primarily sources accept shorter commands. This subsystem contains commands that program power supply parameters or commands that query programmed power supply parameters (for example: programmed values for current and voltage, programmed values for step current and step voltage, lowest or highest value possible to program for current and voltage etc.
CURR:STEP 0.2 CURR UP ;program current step value ;increase output current CURR:STEP 0.5 CURR DOWN ;program current step value ;decrease output current Note: If no step value was programmed before CURR UP or CURR DOWN commands, default step value (0.001 A) will be used. CURRent[:LEVel][:IMMediate]:TRIGgered[:AMPLitude] {|MIN|MAX} This command allows you to program the current trigger value, which is transfered to the output terminals when a trigger signal occurs.
:VOLTage[:LEVel][:IMMediate]:STEP[:INCrement] {|DEFault} This command allows you to set the voltage step for VOLT UP or VOLT DOWN command. The default value for voltage step is 10 mV. :VOLTage[:LEVel][:IMMediate]:STEP[:INCrement]? [DEFault] This command queries the programmed voltage step value (if no parameter specified), or the default voltage step value (if DEFault parameter is specified within the command) for voltage. The returned value is specified in Volt.
:VOLTage:PROTection[:LEVel]? [MIN|MAX] This command queries the programmed voltage protection level. When using MIN or MAX parameters, the power supply returns the lowest or the highest value that is possible to program for voltage protection level, depending on the parameter. :VOLTage:PROTection:S TATe {0|1|OFF|ON} This command allows you to disable / enable the overvoltage protection circuit.
OVP circuit is enabled. If output voltage becomes equal or greater than OVP programmed trip level, OVP circuit trips and Over Voltage and Output Off messages will be displayed. Output voltage will become 0 V. It is not necessary to check every setting with the interogative command! This is an example of how you use this commands.
Let’s say that the output voltage is lower than 10V. No load connected. VOLT:PROT 10 VOLT:PROT:STAT ON ;program OVP trip level ;enable OVP circuit If OVP circuit is already enabled, you don’t have to enable it again! VOLT 10 ;OVP circuit tripped When output voltage becomes equal or greater than OVP trip level (here is 10V), OVP circuit trips. Output is disabled and Over Voltage message will be displayed. VOLT 5.5 VOLT? ;decrease output voltage level ;returns programmed output voltage (5.
When output voltage becomes equal or greater than OVP trip level (here is 8V), OVP circuit trips. Output is disabled and Over Voltage message will be displayed.
STATus Subsystem This subsystem controls SCPI defined status reporting structures. STATus:QUEStionable:EVENt? This command queries Status Questionable Even Register. The power supply returns a decimal value which is the binary weighted sum of all bits of the register. Reading Status Questionable Event Register does not clear it. STATus:QUEStionable:ENABle This command sets Status Questionable Enable Register. This is a mask register.
SYSTem Subsystem This subsystem contains functions that are not directly related to power supply performance. :SYSTem:BEEPer[:IMMediate] This command determines the power supply to generate a beeper right after she received this command. SYSTem:COMMunicate:GPIB:RDEVice:ADDRess This command will change the power supply’s GPIB address. SYSTem:COMMunicate:GPIB:RDEVice:ADDRess? This command queries the power supply’s GPIB address.
TRIGger Subsystem The power supply has a trigger subsystem, so voltage and current values can be changed when receiving a trigger signal. Depending on the trigger source selected, this change takes place immediately (when receiving the trigger signal), or after a time period equal with the delay you set (a time period from the moment the power supply receives the trigger signal) To activate the trigger subsystem you must follow the steps described bellow: 1. Specify the source of the trigger signal.
At power on reset or *RST command, voltage and current trigger values are the programmed values (values displayed in limit mode) until you explicitly program them with the desired values. So before programming voltage and current values, :VOLTage[:LEVel][:IMMediate]:TRIGgered[:AMPLitude]? and :CURRent[:LEVel][:IMMediate]:TRIGgered[:AMPLitude]? commands return the programmed values for voltage and current.
Here are described the commands used to set trigger subsystem’s parameters: :CURRent[:LEVel][:IMMediate]:TRIGgered[:AMPLitude] |MIN|MAX} This command allows you to program the current trigger value, which is transfered to the output terminals when a trigger signal occurs. By programming this value, you don’t change the current programmed value. Instead of a numeric value, you can use MIN or MAX parameters. MIN allows you to set the lowest current value, which is 0 V.
MAX parameter allows you to set the trigger delay to 36,000 seconds (equivalent to 10 hours). At power on reset or after *RST command this value is set to 0 seconds. :TRIGger:DELay? [MIN | MAX] This command queries the trigger delay programmed value. When using MIN or MAX parameters, the power supply returns the lowest and the highest value that are possible to program for trigger delay.
Non-SCPI Commands SET {|DEF|MIN|MAX}[,|DEF|MIN|MAX] This is a non-SCPI command. This command allows you to program output voltage and current values in the same time, using one command only. Using this command, you can program output voltage or output voltage and current values. So if you specify one parameter only, it is considered as voltage programming value. Instead of using numeric parameters for current and voltage values, you can use DEFault, MIN or MAX parameters.
IEEE 488.2 Commands The 488.2 specifications include some instrument commands and a status information scheme. For more information about SCPI Status Registers, see Status Reporting Overview section. *CLS (Clear Status) This command clears Status Byte Register and all the Event Registers summarized in Status Byte, such as Questionable Status Event Register and Standard Event Register.
*OPC? The power supply returns an ASCII “1” after all operations, including this command are executed. *RST This command allows you to reset the power supply. The power supply reset can be achieved by sending this command or by selecting RESET option from the Recall menu (Recall key). The power supply reset values for different parameters are listed in Technical Specifications section. *SAV {0 | 1 | 2 | … | 99} This command saves the current state of the power supply in the specified location.
IEEE 488 Bus Commands These comands are GPIB / 488 interface specific commands. In command mode (ATN line low), the power supply can receive three classes of commands: Talk and Listen addresses: They define which device from GPIB interface will be the active Talker and which devices will be the active Listeners. When ATN line is true, all devices must wait for the commands: listeners an talker will be assigned. Universal commands: they are commands sent by the Controller to all devices from GPIB interface.
Addressed commands: they are byte commands sent by the Controller only to the addressed Listeners. So these commands are sent with address bytes. GET (Groupe Execute Trigger) This command is equivalent to the *TRG command. For more information about trigger subsystem of the power supply, please refer to Trigger Subsystem section. SDC (Selected Device Clear) Resets the power supply to its default state. This command is equivalent to the *RST command, so the power supply will go to reset state.
ASCII Table For GPIB Ch NUL SOH STX ETX EOT ENQ ACK BEL Ctrl ^@ ^A ^B ^C ^D ^E ^F ^G Cmd BS HT LF VT FF CR SO SI ^H ^I ^J ^K ^L ^M ^N ^O GET TCT DLE DC1 DC2 DC3 DC4 NAK SYN ETB ^P ^Q ^R ^S ^T ^U ^V ^W BS HT LF VT FF CR SO SI ^H ^I ^J ^K ^L ^M ^N ^O GTL SDC PPC LLO DCL PPU SPE SPD Dec 0 1 2 3 4 5 6 7 Hex 0 1 2 3 4 5 6 7 Ch Sp ! “ # $ % & ‘ Cmd L0 L1 L2 L3 L4 L5 L6 L7 Dec 32 33 34 35 36 37 38 39 Hex 20 21 22 23 24 25 26 27 8 9 10 11 12 13 14 15 8 9 a b c d e f ( ) * + , -.
Ch @ A B C D E F G Cmd T0 T1 T2 T3 T4 T5 T6 T7 Dec 64 65 66 67 68 69 70 71 Hex 40 41 42 43 44 45 46 47 Ch ‘ a b c d e f g Cmd SC0 SC1 SC2 SC3 SC4 SC5 SC6 SC7 Dec 96 97 98 99 100 101 102 103 Hex 60 61 62 63 64 65 66 67 H I J K L M N O T8 T9 T10 T11 T12 T13 T14 T15 72 73 74 75 76 77 78 79 48 49 4a 4b 4c 4d 4e 4f h i j k l m n o SC8 SC9 SC10 SC11 SC12 SC13 SC14 SC15 104 105 106 107 108 109 110 111 68 69 6a 6b 6c 6d 6e 6f P Q R S T U V W T16 T17 T18 T19 T20 T21 T22 T23 80 81 82 83 84 85 86 87
The SCPI Status Registers Status reporting scheme is described in this section.
Event Register is a read only register. Bits in an event register are set depending on the state of the power supply. An event register is cleared after its value was queried or by sending *CLS command. A *RST command does not clear event registers. When an event register is queried, the power supply returns a decimal value, which is the binary – weighted sum of all bits of the register.
Standard Event Register Standard Event Register reports different instrument events, such as: query errors, device dependent error, execution errors, command errors, power on event. A set bit indicates that an event of the specified type occurred.
Status Byte Register Status Byte Register reports conditions from the defined status registers, depending on the bits from the enable registers. So clearing an event register will clear the coresponding bits from the Status Byte Register. Bits 0..
Error Messages There are 2 kinds of errors that will be generated by the power supply: ♦ standard errors (errors defined by SCPI standard, in [-299,-100] interval) ♦ device specific errors (user defined errors, in [-399,-300] or [1,32767] interval) Following types of errors may occur: ♦ Command errors (defined by SCPI standard) ♦ Execution errors (defined by SCPI standard) ♦ Device-specific errors (defined by SCPI standard) ♦ Self test errors (device specific errors, user defined) ♦ Calibration errors (devi
Error -123: Exponent too large The numeric parameter received has an exponent larger than 32,000. Error -124: Too many digits The decimal numeric parameter has a mantissa which contains more than 255 digits, excluding leading zeros Error - 128: Numeric data not allowed A legal numeric data element was received, but is not the right data element for the header Error -131: Invalid suffix The received suffix for the numeric parameter is not specified for this device.
Execution Errors Error – 211: Trigger ignored *TRG command was received, but it was ingnored because trigger subsystem was not initiated (using INITiate command). Error - 222: Data out of range The numeric parameter value is out of range. Error - 223: Too much data A legal string program data element contains more data than the device could handle due to memory or due to device specific requirements.
The communication session was interrupted before it was finished (no terminator was sent). Err -410: Query interrupte d A command was received before the response to the previous interrogative command was sent. Err -420: Query unterminated The power supply was addressed to talk (to send data over the interface), but it didn’t previously receive a command which sends data to the output buffer (an interrogative command).
Error 611: EEPROM absent Error 612: ADC offset register V checksum failed Error 613: ADC offset register I checksum failed Error 614: DAC offset register V checksum failed Error 615: DAC offset register I checksum failed Error 616: ADC full gain register V checksum failed Error 617: ADC full gain register I checksum failed Error 618: DAC offset register OVP checksum failed Error 619: DAC V step register checksum failed Error 620: DAC I step register checksum failed Error 621: DAC OVP step register checksum
If one of the errors above is generated, the power supply must be turned off and then turned on. If one of these errors is generated again, the power supply must be delivered to B&K Precision for service. Calibration Errors Here are calibration error messages generated by the power supply: Error 637: Secure code checksum failed If this error is generated, the power supply must be unsecured using hardware unsecure procedure. After that, the power supply must be secured.
Error 724: DAC V step register memory bad Error 725: ADC full gain register V out of range Error 726: ADC full gain register V memory bad Error 731: DAC offset register OVP start value out of range Error 732: DAC offset register OVP out of range Error 733: DAC offset register OVP memory bad Error 734: DAC OVP step register start value out of range Error 735: DAC OVP step register out of range Error 736: DAC OVP step register memory bad Error 741: Imon register out of range Error 742: ADC offset register I
CC fault CV fault In this case, the power supply must be turned off and then turned on. If the messages persist, the power supply must be delivered to B&K Precision for service.
Technical specifications Table 1: Technical S pecifications for 9120 Model Parameter Output Ratings (at 0 ° - 40 ° C) 9120 0 to + 30 V / 0 to 3 A Programming Accuracy [1] Voltage < 0.05%+10 mV 12 months ( at 25 ° C±5° C) ± (% of output + offset) Current < 0.2%+10 mA Readback/Meter Accuracy[1] Voltage < 0.05%+5 mV 12 months(over RS 232 or front panel with respect to actual output at 25 ° C ± 5° C) ± (%of output + Current < 0.
Table 2: Technical S pecifications for 9121 Model Parameter 9121 Output Ratings (at 0 ° - 40 ° C) 0 to + 20 V / 0 to 5 A Programming Accuracy [1] Voltage < 0.05%+10 mV 12 months ( at 25 ° C±5° C) ± (% of output + offset) Current < 0.2%+10 mA Readback/Meter Accuracy[1] Voltage < 0.05%+ 5mV 12 months(over RS 232 or front panel with respect to actual output at 25 ° C ± 5° C) ± (%of output + Current < 0.
Table 3: Technical S pecifications for 9122 Model Parameter 9122 Output Ratings (at 0 ° - 40 ° C) 0 to + 60 V / 0 to 2.5 A Programming Accuracy [1] Voltage < 0.05%+10 mV 12 months ( at 25 ° C±5° C) ± (% of output + offset) Current < 0.2%+10 mA Readback/Meter Accuracy[1] Voltage < 0.05%+5 mV 12 months(over RS 232 or front panel with respect to actual output at 25 ° C ± 5° C) ± (%of output + Current < 0.
Table 4: Technical Specifications for 9123 Model Parameter 9123 Output Ratings (at 0 ° - 40 ° C) 0 to + 30 V / 0 to 5 A Programming Accuracy [1] Voltage < 0.05%+10 mV 12 months ( at 25 ° C±5° C) ± (% of output + offset) Current < 0.2%+10 mA Readback/Meter Accuracy[1] Voltage < 0.05%+5 mV 12 months(over RS 232 or front panel with respect to actual output at 25 ° C ± 5° C) ± (%of output + Current < 0.
[1]Accuracy specifications are after an 1-hour warm-up with no load and calibration at 25° C Transient Response Time Less than 50µsec for output to recover to within 15mV following a change in output from full load to half load or vice versa.
Supplemental Characteristics Remote sensing capability Voltage drop Up to 1V per each lead Load regulation Add 5mV to spec for each 1-volt change in the + outputs lead due to load current change. Load voltage Substract voltage drop in load leads from specified output voltage rating. Temperature coefficient, ±(% of output+offset) Maximum change in output/readback per Voltage < 0.02%+2mV Current °C after a 30-minute warm-up: < 0.
AC Input Ratings (selectable via the line vol tage receptacle switch): 115 Vac ± 10 % for 47 to 63 Hz 230 Vac ± 10 % for 47 to 63 Hz Line voltage selection: The line fuse is located in the space just below the input receptacle. To change line voltage values first remove fuse holder and then remove tan colored fuse bracket. The line voltage value is determined by value shown through the window of the fuse holder. Please ensure correct insertion and fuse rating. Fuse ratings: Model 9120: 3.
Programming Ranges The power supply parameters are programmed using command of SOURce subsystem. Here are programming ranges, programming values for MINimum, MAXimum, DEFault parameters and reset state: Table 5: Programming ranges for voltage parameter Voltage parameters Programming range MINimum MAXimum DEFault Reset Model 9120 0 to 30.5V 0V 30.5 V 0V 0V Model 9121 0 to 20.5V Model 9122 0 to 30.5V 0V 20.5 V 0V 0V 0V 60.5 V 0V 0V Model 9123 0 to 30.5V 0V 30.
Reset Values Here are the power supply parameter values after a *RST command or after recalling Reset state. Table 8: Reset values for power supply parameters Power supply parameters Voltage Voltage step Voltage trigger OVP circuit state OVP trip level Current Current step Current trigger Display state Output state Trigger delay Trigger source Model 9120 0V 0.01 V 0V ON 33 V 3.00 A 0.001 A 3.00 A ON OFF 0s BUS Model 9121 0V 0.01 V 0V ON 22 V 5.00 A 0.001 A 5.00 A ON OFF 0s BUS 113 Model 9122 0V 0.
Interface Cable In order to command the power supply over the remote interface, you must connect it to a computer terminal. Usually, the computer terminals are DTE (Data Terminal Equipment). The power supply is also DTE, so you need a DTE to DTE interface cable. These cables are called null-modem or crossover cables. There are 2 types of serial connectors: DB-9 and DB-25. The power supply has a male DB-9 connector.
Limited One -Year Warranty B&K Precision Corp. warrants to the original purchaser that its product and the component parts thereof, will be free from defects in workmanship and materials for a period of one year from the data of purchase. B&K Precision Corp. will, without charge, repair or replace, at its’ option, defective product or component parts. Returned product must be accompanied by proof of the purchase date in the form a sales receipt. To obtain warranty coverage in the U.S.A.
This warranty gives you specific rights and you may have other rights, which vary from state-to-state. Model Number: ______________ Date Purchased: __________ 22820 Savi Ranch Parkway Yorba Linda, CA 92887 714.921.9095 714.921.
Service Information Warranty Service: Please return the product in the original packaging with proof of purchase to the below address. Clearly state in writing the performance problem and return any leads, connectors and accessories that you are using with the device. Non-Warranty Service: Return the product in the original packaging to the below address. Clearly state in writing the performance problem and return any leads, connectors and accessories that you are using with the device.
PN: 481-533-9-001 Printed in Romania 2004 B&K Precision Corp. 118 22820 Savi Ranch Parkway Yorba Linda, CA 92887 USA TEL: 714-921-9095 FAX: 714-921-6422 www.bkprecision.
