Rockwell Automation 1760-xxxx Pico Controller User Manual - Manual (Page 164)

Publication 1760-UM001D-EN-P - September 2005
7-14 Retention
Retentive Up/Down
Counters C7 and C8 How the Retention Works
The actual values of counters C7 and C8 are retentive. When the
condition for resetting the counter is satisfied, the actual value of the
counter will be reset.
Examples
Counting Parts
Task 1
Parts are packed automatically in a shipping carton. Even if there is a
power outage, the correct number should still be packed into the
carton. When the carton is full, the carton is removed manually and
the counter is reset.
Contacts and relays used:
Signal diagram:
U = Supply voltage
Coil Function
I5 Count parts
I6 Reset counter
Q1 Carton Full, signal lamp
C8 Up counter
DIR
CNT
RES
C8
+
{
I5---------CC8
C8---------{Q1
I6-C8------RC8
0042 0036
Circuit Diagram: Parameters entered:
U
a a