Emerson PACSystems RX3i - Figure 29: RTU Read Exception Status Message Format

PACSystems™ RX3i and RSTi-EP CPU Reference Manual Section 6
GFK-2222AK October 2019
Serial I/O, SNP & RTU Protocols 176
6.3.3.6.3 Response:
The normal response to a preset single register query is identical to the query. Message
(07): Read Exception Status
6.3.3.6.4 Format:
Figure 29: RTU Read Exception Status Message Format
Address
Error Check
Func
07
Query
Normal Response
Address
Data
Error Check
Func
07
6.3.3.6.5 Query:
This query is a short form of request for the purpose of reading the first eight output
points.
▪ An Address of zero is not allowed as this cannot be a broadcast request.
▪ The function code is equal to 07.
6.3.3.6.6 Response:
The Data field of the normal response is one byte in length and contains the states of
output points one through eight. The output states are packed in order of number with
output point one’s state in the least significant bit and output point eight’s state in the
most significant bit.