Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 111)

Chapter 10
Using Remote I/O
10 – 19
CONTINUOUS N
BTR BTW
ENABLE ENABLE
BTR
BLOCK TRNSFR READ-
RACK
GROUP
MODULE
CONTROL BLOCK
DATA FILE
LENGTH
CONTINUOUS N
BTR BTW
ENABLE ENABLE
BTW
BLOCK TRNSFR WRITE
RACK
GROUP
MODULE
CONTROL BLOCK
DATA FILE
LENGTH
NOTE: The Block Transfer Read instruction is required if DL40 data is to be
returned to the PLC or if the Handshake Enable DIP switch is in the ON
position.
Triggering a Message (Block Transfer Write)
•
Message/Variable/Slave Run Mode – Block Transfer Write Length can be
3 to 13 words. If Length is set to 0, a default length of 13 will be used.
The DL40 always interprets the last word as a slave address. If more than
13 words are sent, the DL40 will interpret the thirteenth word as a slave
address and ignore the rest.
Note: Word 13 = 0 tells the DL40 to use the slave address selected as a
message attribute.
•
Message/Variable Run Mode – Block Transfer Write Length can be 2 to
12 words. If Length is set to 0, a default length of 12 will be used. If
more than 12 words are sent, the DL40 accepts the first 12 words and
ignores the rest.