Rockwell-automation 1797-OE8H FLEX Ex HART Analog Modules User Manual Manual de usuario descargar pdf (Pagina 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

2bytes)

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

1 2 ... 142 143 144 145 146 147 148 149 150 151 152 ... 195 196

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Rockwell-automation 1797-OE8H FLEX Ex HART Analog Modules User Manual Manual de usuario Pagina 147