Programming Technique
Chapter 25
25-8
Figure 25.7
Recording Temperature Values Every 5 Seconds
200
100
X
202
000
G
201
009
G
X
203
900
203
900
:
205
180.000
G
204
005
G
206
:
205
180
212
G
207
032
G
210
+
030
15
TON
1.0
030
PR 005
AC 000
030
15
JSR
02
LBL
06
RET
SUBROUTINE AREA
Here is an explanation of each rung:
Rung 1:
When rung 1 is true, the timer (this is an example of a free
running timer) starts.
Rung 2:
The JSR instruction jumps to the subroutine area label
instruction when the timer’s accumulated value reaches
5 seconds.
Rungs 3-5: Converts Celsius temperature to Fahrenheit temperature
exactly as in application one.
Rung 6:
The Return instruction signals the processor to return to
the main program area.
ATTENTION: You should make allowances for conditions
which could be created by the use of the Jump To Subroutine
instruction. The processor does not scan the subroutine
program unless initiated by a Jump To Subroutine in the main
program. Timers and counters within these rungs cease to
function. You should reprogram critical rungs in the main
program area.
