Elster Instromet 2000 - Appendix 3 c Siemens Optichrome Chromatograph

Model 2000 Flow Computer Instruction Manual
APPENDIX 3 GAS CHROMATOGRAPHS SUPPORTED
Model 2000 issue 21 Page No
79
APPENDIX 3c Siemens Optichrome Chromatograph
Gas Component Default Address Number Format
Status 30001 unsigned 16 bit integer
Unit will continue to read the above register until the following conditions are correct
30001 is greater than the alarm limit value
When these conditions are met it will continue to read addresses 41701 to 43101
Gas Component Default Address Number Format
Nitrogen N2 41701 unsigned 16 bit integer
Carbon Dioxide CO2 41901 unsigned 16 bit integer
Rel dens 42701 unsigned 16 bit integer
Superior Heating Value Hs 42601 unsigned 16 bit integer
Inferior Heating Value Hi 42801 unsigned 16 bit integer
Methane C1 41801 unsigned 16 bit integer
Ethane C2 42101 unsigned 16 bit integer
Propane C3 41201 unsigned 16 bit integer
i-Butane i-C4 41301 unsigned 16 bit integer
n-Butane n-C4 41401 unsigned 16 bit integer
i-Pentane i-C5 41501 unsigned 16 bit integer
n-Pentane n-C5 41601 unsigned 16 bit integer
C6+ 41101 unsigned 16 bit integer
Wobbe (superior) 43101 unsigned 16 bit integer
The Siemens Optichrome interface supports the Following Modbus commands only
1) Read requests of Data Registers
[T1-T2-T3-T4]KK03ssssnnnn<CRC>[T1-T2-T3-T4]
2) Read requests of Status Registers
[T1-T2-T3-T4]KK04ssssnnnn<CRC>[T1-T2-T3-T4]
3) Force Single Coil Instruction (Sent Automatically every 10 seconds)
[T1-T2-T3-T4]KK05<FF00><CRC>[T1-T2-T3-T4]
The Expected responses to the above packets from the GC are as follows:-
1) Valid Data Read Requests:
[T1-T2-T3-T4]KK03bb<DATA><CRC>[T1-T2-T3-T4]
2) Valid Status Read Requests:
[T1-T2-T3-T4]KK04bb<DATA><CRC>[T1-T2-T3-T4]
3) Force Single Coil Instruction
[T1-T2-T3-T4]KK05<FF00><CRC>[T1-T2-T3-T4]
Where:
a) [T1-T2-T3-T4] is at least 3.5 character times of silent interval.
b) KK is the identification number.
c) 03 hex is the Modbus code "Read multiple holding registers".
d) 04 hex is the Modbus code "Read Input register".
e) 05 hex is the Modbus code "Force Single Coil".
f) ssss is the start address in the range 0000 to FFFF (0 to 63535 decimal).
g) nnnn number of registers in the range 0001 to 00FF (1 to 255 decimal).
h) bb is the number of bytes to be transferred.
i) <FF00> is the Single Coil address.
j) <DATA> data nnnn items.
l) <CRC> CRC Checksum.