100
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Appendix A - MODBUS RTU Protocol
byte 4: CRC_Low
($XX)
byte 5: CRC_High
($XX)
Note:
There are cases where the ASTAT-XT returns the Normal response, but the requested action cannot be performed or
is modified by the ASTAT-XT. Few examples are:
Requested Action
Performed Action
Write Parameter settings during
start
process
Ignored.
Write multiple parameters (Function 16), some are out of range
Limit to allowed range.
Start command (Function 05) while Stop Hardwired Input is open
Command ignored
It is the user’s responsibility to verify that the requested action was performed, by reading the value of the modified
parameters or the status of the command Coils.
