Rockwell Automation 1797-OE8H FLEX Ex HART Analog Modules User Manual - Manual (Page 147)

Publication 1797-6.5.3 - March 2006
FLEX Ex HART Module Commands B-23
Command 158
The Read Special Loop SCAN Parameters command returns the transmitter
data for the given loop, if available. These include:
• Loop number
• Error flag (0 = ok, 1 = special SCAN not active)
• Polling address (always 0, no multidrop)
• Selected SCAN command
• Long frame address
• Number of available data bytes
• Data bytes themselves (if any)
Table B.26 Command 158 Request and Response Data Bytes
Byte Description Value
Request Data Bytes
0 CH_NUM Channel number 0…7
Response Data Bytes
0 CH_NUM Channel number 0…7
1 ERROR Error 0 = Special scan
set up for the
selected channel
1 = Special scan
not set up (reply
is truncated to
2 bytes)
2 SHORT_ADDR Short address used —
3 THRESH Threshold data length for special scan 0…62
4 SCAN_CMD Scan command being used —
5…9 EXT_ADDR Extended address of instrument
10 LENGTH Length of data bytes available > 0 if data
available
11… DATA Special scan data (if any) —
Command-specific Response Codes
2 Error Invalid selection
5 Error Too few data bytes received
16 Error Access restricted
32 Error Busy