Allen-Bradley controllogix 1756-L63, User Manual

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Publication 1756-UM001E-EN-P - August 2002
Communicate with 1771 I/O Over a ControlNet™ Network 9-15
Send a Block Transfer Read Message
1. Enter the following rung:
The MSG instruction reads the input values from a BT module and stores the values in BTR_int_buffer_read .
•
Each time the instruction is done, it automatically restarts and sends another message.
•
Prior to each message, the series of MOV and COPY instructions load the appropriate configuration properties into
the MSG instruction so it can read the next BT module. The configuration properties load from the
BTR_cfg array.
•
After each MSG, a subsequent rung increments the BTR_index tag. This loads the configuration properties for the
next module into the MSG instruction before it executes again.
43020
Tag Name: Description: Data Type: Scope:
BTR block transfer message that reads data from
each BT module MESSAGE
name_of_controller
(controller)
BTR_cfg array of configuration properties for each BT
module BT_CONFIGURATION
[
number
]
name_of_controller
(controller)
BTR_index controls which BT module that the MSG
instruction reads DINT
name_of_controller
(controller)
Where: Is the:
number
number of modules that this message reads
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