Rockwell Automation 1771-TCM,D17716.5.108 TEMPERATURE CONTROL MOD - Manual (Page 27)

Chapter 3
Communicating with Your Module
3-5
The following figure shows an example of PLC-5

ladder logic to handle
data single-transferred to/from the 1771-TCM module in an application
where the control variable TPO of each loop is used for only heating.
BTD
BIT FIELD DISTRIB
Source
Source bit
Dest
I:001
35
8
O:002
Dest bit
Length
0
0
8
BTD
BIT FIELD DISTRIB
Source
Source bit
Dest
35
0
O:001
Dest bit
Length
9984
8
8
MEQ
MASKED EQUAL
Source
Mask
I:001
35
00FF
Compare 35
I:001
7
BTD
BIT FIELD DISTRIB
Source
Source bit
Dest
0
0
O:002
Dest bit
Length
0
0
8
This rung examines the low byte of TCM
module's input image word to see if it is equal
to 35
10
. If true, it copies the high byte of the
TCM module's input image word to the output
image byte of the module driving the heating
elements.
This rung unconditionally writes the value 35
10
to the high byte of the TCM module's input
image word.
If the TCM module's watchdog timer bit is off,
this rung zeros the output image byte of the
outputs driving the heating elements.
Since this instruction is designed primarily
for use with integer source and destination
words, the source bit and destination bit
must be designated in decimal. In these
cases you would enter 8
10
to designate bit
10
8
of the I/O image word
I:001
6
I:001
0
In this example:
the 1771-TCM module and the output module driving the heating
elements 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)