Rockwell Automation 1771-TCM,D17716.5.108 TEMPERATURE CONTROL MOD - Manual (Page 30)

Communicating with Your Module
Chapter 3
3-8
In this example:
the 1771-TCM module the output modules driving the heating and
cooling elements, and the input module providing the input for the
manual-start pushbutton switch are in the same I/O chassis with the
PLC-5 processor
the chassis is set for 1-slot addressing
the 1771-TCM module is in slot 1 (I/O group 1)
the module driving the heating elements is in slot 2 (I/O group 2)
the module driving the cooling elements is in slot 3 (I/O group 3)
the module providing the input for the manual-start pushbutton switch is
in slot 4 (I/O group 4)
To generate a block-transfer to the 1771-TCM module, your ladder logic
must execute a block-transfer write instruction. To generate a
block-transfer from the 1771-TCM module, your ladder logic must execute
a block-transfer read instruction.
Enter the rack number and group number based on the module’s physical
location as with any other block-transfer module. The module entry
specifies the byte (0 or 1) of the I/O image word. Although the module
uses a full word of I/O image space, the low byte of the module’s I/O
image word is used for block-transfer. Therefore, in the block-transfer
instruction, you must address the 1771-TCM module as module 0.
BTR
BLOCK TRANSFER READ
Rack
Group
Module
Control block
0
Data File
Length
Continuous
Always enter module 0
Your ladder logic will need to execute the block-transfer write instruction
upon specific events to transfer the specific write blocks. Your ladder logic
will need to execute the block-transfer read instruction on a regular basis at
timed intervals. Since the module updates the read block data at a rate of
only approximately once per second, executing the block-transfer read
more often then that does not provide any benefit.
Block Transfer
Programming