Teledyne 9060 - Zirconium oxide flue gas oxygen analyzer - Manual (Page 89)

9060-Zirconia Analyser
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APPENDIX 6
MODBUS™ Register Map and Application Notes
MODBUS™ Functions Supported are:-
ReadHolding Register Function 3
WriteHolding Register Function 6 ( for allowable addresses only )
Introduction.
The
9060 Analyser implements the MODBUS™ slave protocol, it is intended to work in
conjunction with a MODBUS™ master.
This is accomplished by setting the MODBUS™ address to some non-zero value in the
range 1-31, setting the jumper positions to select the RS485 half duplex configuration, and
re-starting the transmitter.
The master must be configured as follows.
Baud
Rate 9600
Parity none
Stop
Bits 1
RS485 Half Duplex
Mode RTU ( binary mode)
A typical transaction would be to read the current value of a variable from the transmitter.
The master send a ReadHoldingRegister packet, with the appropriate address and the
transmitter responds with data at that address.
The Register Addresses are as follows, to convert to Schneider addresses for earlier
model PLC's address space, add 40001 to each address.
or for later model PLC's with linear address space the address co-responds directly to
%MW XXXX address.
For Example, to read probe temperature set-point -
Read %MW1436 which is equivalent to holding register 41437 = 40001 + 1436
Some data is 32 bit data (double) which requires some care to ensure that the word order
is correctly interpreted.
For Example, OXYGEN32, (dual probe) which is at address 2052 is interpreted as follows.
2052 contains the high 16 bits for probe 1 oxygen
2053 contains the low 16 bits for probe 1 oxygen
2054 contains the high 16 bits for probe 2 oxygen
2055 contains the low 16 bits for probe 2 oxygen