CHAPTER 4. APPLICATION DESIGN Stop-onStall 57 You can enable the Stop-on-Stall function with the FSDI command. The move will terminate. without any delay. as soon as a stall is detected This function works either in Motor Step or Encoder Step mode. CAUTION DIsabIlDg the Stop-Gn-StaD function with the FSD(l) command wID allow the AX to 8nIsh the move regard1e88 of a stan detection, even if the load 18 jammed. Thls can potentla11y damage user equipment.
58 AX DRIVE USER GUIDE Determining Backlash You can measure the actual backlash with the following procedure. The idea is to move in one direction, stop, and make a series of one-step moves in the opposite direction. No change in encoder position occurs while the indexer takes up the backlash. The number of motor steps counted before any encoder counts are received is the measure of the backlash. NOTE: When the en.
CHAPTER 4. APPLICATION DESIGN Output-On- Stall 59 You can select the Output-on-Stall function with the Turn on Output # 1 on Stall Detect (FSE) command. This is useful for signaling other components in your system that a stall has occurred. If you enter the FSE 1 command. the AX programmable Output # 1 goes on (current flows) when a stall is detected and remains on untn a new move begins.
60 AX DRIVE USER GUIDE Output on Position Loss The Turn on Output #2 When Within Dead Band (FSG) command allows the AX to signal other system components when the motor ts within the dead band. Thts command is valid only if Stall Detection (FSH1) has been enabled: it will have no effect otherwise. At the end of the move, if the motor is within the specif1ed dead band (DB), Output #2 wUl be turned on.
CHAPTER 4. APPLICATION DESIGN 61 Program Control Triggers You can use the Wait for Trigger (TR) conunand to specify a configuration of trigger conditions to be matched before executing a sequence of buffered commands. The trigger inputs are lRIG 1. lRIG 2. and lRIG 3.
2 AX DRIVE USER GUIDE LoopS Single Loops This section discusses methods of establishing loops in the programs you write for you application. Loops can be created individually or nested within each other. You may use the Loop (L) command to repeat certain programs the one provided below. All the commands between the L command and the N command are looped (repeated) the number of times indicated in the L command.
CHAPTER 4. APPLICATION DESIGN POSs (Programmable Output Bits) You can turn the programmable output bits (our 1 and our 2) on and off using the Output (0) command. You can use the outputs to signal remote controllers. tum on LEOs. sound bU72ers, etc. A one (1) turns on a given output, a zero (0) turns the output off. and an X leaves the output unchanged. The outputs conduct current when they are on and do not conduct when they are off (see the 0 command description in Chapter 5. Software Reference).
64 AX DRIVE USER GUIDE Example '3 Command PS MN A2 V2 D384"" G 01X C Qescription Pauses execution until indexer receives a Continue (C) command Sets move to normal mode Sets acceleration to 2 revs/sec2 Sets velocity to 2 rps Sets distance to 38,400 steps Executes the move (Go) Turns on Output 1 Cancels the Pause and executes the move The motor moves 38.400 steps. When the AX completes the move. Output 1 is turned on.
CHAPTER 4. APPLICATION DESIGN 65 It Is a good practise to erase the sequence with the XE command before defining the sequence with the XD command. To begin the definition of a sequence. enter the XD command immediately followed by sequence identifier number (1 to 7) and a delimiter (pressing the space bar or the carriage return key). The XT command ends the sequence definition and automatically loads the sequence into the AX's EEPROM.
66 AX DRIVE USER GUIDE Stand-alone Operation Power-up Sequence Execution This section explains and provides examples of how to store sequences to be automatically executed when you power-up the system. or executed by remote switches. You will first have to define the sequences into the AX non-volatile memory. You will need a computer or PLC with RS-232C communication capabUities for programming the AX . A single.
CHAPTER 4. APPLICATION DESIGN 67 When in the XP9 mode, it is possible to cause the AX to pause between sequence execution. This is done with the XQl command. When the XQl command is present within a sequence, the AX will pause after the execution of the sequence and will wait for all sequence select inputs to be OFF (see sequence #8 in Table 4-2). The AX will then read the status of the sequence select inputs and execute the corresponding sequence number.
68 AX DRIVE USER GUIDE STEP 5 Cycle Power or enter the Z command. The AX will go through the nonnal XP9 mode operation. In XP9 mode, the AX scans the sequence select inputs, looking for a valid sequence according to the binary value of the three inputs (see Table 42). STEP 6 Momentarily tum on (ground) the SEQ 2 input. This will execute sequence number 6. NarE: After the sequence has finished executing, the inputs are again scanned to execute another sequence.
CHAPTER 4. APPLICATION DESIGN Single-Axis Control Single-Axis Interface Program Example The AX system is capable of single and multiple axis applications. The principles developed for a single-axis system apply as well to multi-axis systems. If you already have BASICA or GW BASIC programming languages on your computer, you may use the following sample program designed to open a serial communication port and send and receive AX commands.
AX DRIVE USER GUIDE 70 , Define move for Axis 1 1000 MOVE1$ = "1A1 1V2 1025,600 1G 1LF" 1005 CLS 1007 LOCATE 12,15: PRINT" DOING MOVE 1 " , Move axis 1. 1010 PRINT #1,MOVE1$ , Read echoes from AX 1015 ECHO$ = INPUT$(23,1) , Wait for line feed from AX 1020 LF$ = INPUT$(l, 1) , indicating end of move.
CHAPTER 4. APPLICATION DESIGN 71 Multi-Axis Device-specific commands require that a device address Control precede them. The AX will not execute a devtce-speciflc command if there is no device address preceding the command. or if the device address setting in the AX does not match the address preceding the command. Universal commands do not require device identifiers preceding them. A universal command with no device address will be executed regardless of the address setting of the AX.
AX DRIVE USER GUIDE 72 Sample Application and Commands Example: Three indexers are on an RS-232C daisy chain. Send the following commands: Command MN AS V1" 1 064"" 20128"" 3D 192"" G Description Sets unit to Preset mode Sets acceleration to 5 revs/sec2 for all three indexers Sets velocity to 10 rps for all three indexers Sets Axis 1 distance to 6,400 steps Sets Axis 2 distance to 12,800 steps Sets Axis 3 distance to 19,200 steps Moves all axes. Unit 1 moves 6.400 steps, unit 2 moves 12.800 steps.
CHAPTER 4. APPLICATION DESIGN 900 ' ********************* ••••• ******** •••••••••••••••••••••••• 901 902 903 ' 904 905 ' 906 ' . .. . Line 1000-1060 sends a move down to the first AX. Computer waits for the Line Feed from the AX indicating that the motor has finished its move. .. . if • • • • • • * •••• ****.********** •••• ***.***.** ••• **************.
74 AX DRIVE USER GUIDE PLe Operation PLC Connections You can use a PLC to execute 7 different sequences that are stored in the AX non-volatile memory. Three outputs from the PLC can be used to execute sequences, and two inputs to the PLC can be used to monitor AX outputs. Assuming your PLC accepts open-emitter outputs, connect the inputs and outputs as shown in Figure 4-4. If not, contact a Compumotor Applications Engineer at (800) 358-9070. !·i·:99t~Yi:i> ~~---{ ;OUTPGT2C·1---. . . . •:.• . :.
CHAPTER 4. APPLICATION DESIGN Sample Applications and Commands 75 This section provides step-by-step procedures to run sequences from your PtC. First. you need to enter the programs into the AX drive. You will need a terminal or a computer with RS-232C communication capability. You need to define the sequences before you can execute them with your PLC's BCD outputs. Using a terminal or a computer. key in the following commands: STEP 1 STEP 2 Issue the XP9 command.
76 AX DRIVE USER GUIDE 4 Cycle Power or enter the Z command. The AX will go through the nonnal XP9 mode operation. In XP9 mode, the AX scans the sequence select inputs and selects and executes the first avallable valid sequence according to the binaIy value of the three inputs (see Table 4-2). After the sequence is executed, the inputs are again scanned to execute another sequence.
CHAPTER 4. APPLICATION DESIGN 77 The recommended system frictional load for a step motor is approximately 5% of the motor's maximum torque capability. For motor specifications and speed/torque curves, refer to Chapter 6, Hardware Reference. The step-to-step accuracy of the step motor should not be confused with the motors absolute accuracy. Absolute accuracy is based on the quality of the mechanical construction of the motor.
78 AX DRIVE USER GUIDE Gauging Motor Resonance Selecting a method of gauging motor resonance can be accomplished in a number of ways; TACHOMETER METHOD Using an oscilloscope to look at the output of a tachometer attached to the motor shaft. The tachometer will output a DC voltage, proportional to speed. This voltage will oscillate around an average voltage when the motor is resonating. The amplitude of this oscillation will be at a maximum when the natural frequency of the motor is located.
CHAPTER 4. APPLICATION DESIGN 79 Tuning Pot "lusting .crewe AX Series Drive Figure 4-5. AX DIP Switch and Tuning Pot Locations STEP 3 STEP 4 Position all four tuning pots to the center of their adjustment range. Start the motor moving at one of the velocities shown below. depending on the motor frame size. These velocities should get you close to the natural frequency of the motor. 57 Series (NEMA 23) 83 Series (NEMA 32) 106 Series (NEMA 42) STEP 5 Adjusting the Drive to the Motor STEP 1 3.
80 AX DRIVE USER GUIDE STEP Adjust phase B offset (pot #2) and phase A offset (pot #3). 3 Alternately adjust these two pots for maximum smoothness as well. These pots adjust the zero (0) crossing point of the current in each phase. STEP Re-Iocate the natural frequency again. 4 Increase and decrease the velocity in small increments (.1 rps and lower) until you have re-Iocated the velocity where the natural frequency seems to be most prominent.
