Rockwell Automation 1336-GM1 Remote I/O Communications Module - Manual (Page 78)

B–14 Supported Block Transfer Messages
Continuous Parameter Value
Read Continuous Parameter Value Read reads a continuous list of
parameters beginning with the starting parameter number.
PLC Block Transfer Instruction Data
PLC request instruction length: 4 words
Drive response instruction length: 5 – 64 words
Figure B.9 Message Structure
Message Operation
This function specified in the request will read a consecutive group of
parameter values from the device, beginning with the starting
parameter number defined in Word 3 of the request. The number of
parameters to be read is defined in Word 2 of the request. The values
will return in the response, beginning with Word 4. If an error has
occurred in reading any of the parameters, Word 1 of the response
will return a value of -32767 and the response word for that parameter
will return a status word instead of a parameter value.
Header
Word 0
PLC Decimal Value
1 Header
Word 1
Data
Word 2
PLC Request
Header Word 0
Header Word 1
Header Word 2
Message Length
Message Length
PLC Decimal Value
1 — Message OK
–32767 — Message Error
Number of Parameter
Drive Response
Number of Parameter
4
Values to Read
Data Word 3
Starting Parameter
Number
5 – 64
Values to Read
Data
Word 3
Data
Word 4
Data
Word 5
Starting Parameter
Number
Data
Word 6
Value 1
•
•
•
•
•
• •
•
•
•
•
•
Value 2
or Error Code
or Error Code
Value 3
or Error Code
Data
Word 63
Value 60
or Error Code