Instruction manual

Info mode
If in doubt of setting of installed transducer, verification of its address is enabled even
without using computer. Power should be connected.
Unscrew transducer cover and shortly press button next to connection terminals (jumper
must be open). Actual adjusted address of transducer is displayed at decimal code. Next press of
button exits info mode and actual measured values are displayed.
Note: No measurement and communication is possible during info mode. If transducer stays in info
mode for longer than 15 s, transducer automatically returns to measuring cycle.
Description of communication protocols
Detailed description of each communication protocols including examples of
communication is available in individual document.
Note: After switching ON the power of the device it can last up to 2 s before the device starts to
communicate and measure!
Modbus RTU
Control units communicate on master-slave principle in half-duplex operation. Only master
can send request and only addressed device responds. During sending of request no other slave
station should respond. During communication, data transfer proceeds in binary format. Each Byte
is sent as eight bit data word in format: 1 start bit, data word 8 bit (LSB first), 2 stop bits
1
, without
parity. Transmitter supports communication speed from 110Bd to 115200Bd.
Sent request and response have syntax: ADDRESS OF DEVICE – FUNCTION – Modbus CRC
Supported functions
03 (0x03): Reading of 16-bit registers (Read Holding Registers)
04 (0x04): Reading of 16-bit input gates (Read Input Registers)
16 (0x10): Setting of more 16-bit registers (Write Multiple Registers)
Jumper and button
Jumper and button are located next to connection terminals. If communication protocol
Modbus is selected the function of jumper and button is as follows:
• Jumper opened – transmitter memory is protected from writing, from transmitter side it is
only enabled to read measured value, writing to memory is disabled (no change of
transmitter address, communication speed and LCD setting is enabled)
• Jumper closed – writing to transmitter memory is enabled by means of User’s software
• Jumper closed and button pressed for longer than six seconds – causes restoring of
manufacturer setting of communication protocol, i.e. sets Modbus RTU communication
protocol, device address sets to 01h and communication speed to 9600Bd (after button press
there is “dEF” message blinking at LCD display. Six seconds later message “dEF” stays
shown, it means manufacturer setting of communication protocol is done).
• Jumper opened and button shortly pressed – transmitter goes to Info mode, see chapter „
Info
mode
“
1
Transmitter sends two stop bits, for receive one stop bit is enough.
5