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61
Rev. C | 2022.02
FCS - Operation Manual
11.2.2 Input Registers
Input registers are the present channel/sensor readings. They are read only. Units are defined
in the configuration holding registers for each channel (for example, Channel 1 registers are
50,028, 50,029 and 50,030).
Scaler: 10
(de 1)
Every channel has its own scaler value. For example, an NO2 gas measurement normally has
1 decimal place, so its scaler value is 100. An ambient NO2 gas measurement of 0.4 ppm
would be represented in the register as 0.4 x 100 = -40
NOTE:
The STEL and TWA values are not valid if the configuration does not enable STEL and
TWA calculations.
Modbus Function 4 (Read Input Registers) or Function 3 (Read Holding
Registers)
Register Address
Description
Range
Units
30,001
30,001
Channel 1
Reading
present gas reading x scaler
LEL, ppm, % vol,
etc.
30,002
30,002 Channel 1 STEL
present STEL reading x
scaler
LEL, ppm, % vol,
etc.
30,003
30,003 Channel 1 TWA
present TWA reading x
scaler
LEL, ppm, % vol,
etc.
30,004
30,004
Channel 1
Alarms
bit encoded contact CETCI
for bit allocation
LEL, ppm, % vol,
etc.