Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 106)

Chapter 10
Using Remote I/O
10 – 14
•
Variable Data (+)
Can only be used in the Message / Variable Run Mode.
•
Variable Data Number
For Discrete I/O, 1 /
4
Rack only. Binary number – sets position of variable
data in message:
0 = First variable in the message
1 = Second variable in the message
2 = Third variable in the message
3 = Fourth variable in the message
The following illustrates the format of the PLC Input and Output Image
Tables and Block Transfer Read and Write files.
Discrete I/O
Triggering a Message
Message/Variable/Slave and Message/Variable are the same except:
•
In Message / Variable / Slave Run mode, the last word (for 1 /
2
, 3 /
4
, full
rack only) of the Output Image Table is always interpreted as the slave
address no matter what slave address was chosen as a message attribute.
Note: 0 = use slave address selected as a message attribute.
•
In Message Number / Variable Run mode, the Output Image Table has no
slave address and the slave address selected as a message attribute is
always used.
WORD 1
17 16 15 14 Message Number
Variable Data
WORD 0
Handshake Bit
BCD Sign Bit
Variable Data Number
Output Image Table - 1/4 rack
Message/Variable/Slave and
Message/Variable Run Modes