MSA Senscient ELDS 1000 series, Руководство по эксплуатации

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Appendix F – MODBUS Communications
Senscient ELDS™
Rev 15 171
GB
Input Applies Content Comment
21 Rx Last SG Month 1 to 12
22 Rx Last SG Day 1 to 31
23 Rx Last SG Hour 0 to 23
24 Rx Last SG Minute 0 to 59
25 Rx Last SG Second 0 to 59
26 Rx No. Good SimuGas Per laser, for a dual laser system a single
SG process will normally produce
+2 counts for No. Good
27 Rx No. Bad SimuGas
28 Rx L0 Last Gas Value ppm.m
29 Rx L1 Last Gas Value ppm.m
30 Rx L0 Last Gas Year Base 2000
31 Rx L0 Last Gas Month 1 to 12
32 Rx L0 Last Gas Day 1 to 31
33 Rx L0 Last Gas Hour 0 to 23
34 Rx L0 Last Gas Minute 0 to 59
35 Rx L0 Last Gas Second 0 to 59
36 Rx L1 Last Gas Year Base 2000
37 Rx L1 Last Gas Month 1 to 12
38 Rx L1 Last Gas Day 1 to 31
39 Rx L1 Last Gas Hour 0 to 23
40 Rx L1 Last Gas Minute 0 to 59
41 Rx L1 Last Gas Second 0 to 59
These are read only and can be read using the Modbus command 0x04 (Read Input Registers).
There are two separate outputs of the measured gas values for the Receiver units. The ‘simple’
form (Inputs 1 and 2) contain the gas value in ppm.m units. These outputs are restricted to the
range 0 to 65535 ppm.m which is sufficient to cover the normal full scale range of most ELDS
variants. The second form of output is used to duplicate the gas results (Inputs 16 to 19) as well as
providing the signal level for each laser (Inputs 12 to 15). For these each output is coded using two
registers, the actual value is then formed using the product of both registers divided by a scaling
factor of 1000. This allows a much greater dynamic range for these outputs (good accuracy is
maintained for values from 0.1 to 4×106. These then greatly extend the quality of output of the gas
results as well as providing a full diagnostic measure of the signal level for each laser.