Specifications

90 209351 REV B Operations Manual, Redundant System Controllers
7.4.4 Example 4
The host computer requests the Priority be set to Polarity #2. The PC request string is
listed below.
The RCP2-1200 replies with the following response string.
Byte
Position
Byte Val-
ue (Hex)
Description
1 AA Frame Sync Byte 1
2 55 Frame Sync Byte 2
3 0 Destination Address of RCP unit
4 A Source address of Request originating PC Host
5 0 Protocol Version Compatibility Field must always be 0
6 6F Request ID byte is set by originator, will be echoed back by respondent
7 0 Command field for “Set” type request
8 0 “System Settings” tag indicates which data from respondent is required in
response frame
9 5 Data Address field indicates the address of the RCP’s Priority Select data
element inside “System Settings”(data element 5)
10 1 Data Length field indicates how many data bytes “System Settings”
requested from RCP (1 byte requested)
11 1 Data Field 1. 1 Indicates that priority must be set to Pol2
12 7F Arithmetic checksum of bytes number 3 through 11
Byte
Position
Byte Val-
ue (Hex)
Description
1 AA Frame Sync Byte 1
2 55 Frame Sync Byte 2
3 A Destination Address of PC request originator
4 0 Source address of RCP respondent
5 0 Protocol Version Compatibility Field must always be 0
6 6F Echo of the Originator’s Request ID byte
7 2 Command field for “Set” type response
8 0 “System Settings” indicates which data from respondent is included in
response frame
9 2 Data Address field omitted and replaced with Error status code. 2 indicates
“No such data” error
10 1 Data Length field indicates how many data bytes “System Settings”
requested from RCP
11 0 Data field 1 contains rejected data
12 7E Arithmetic checksum of bytes number 3 through 11