Watlow Series 920 Microprocessor-Based Ramping Control - Manual (Page 39)

Nested LOOP
A “Nested” loop is a jump loop within a loop. You will be forced to a step either
forwards or backwards from your present location. When nested loops are
performed, they cannot break across other loops. Your JC can be from 0 - 100
with 0 being an infinite looping.
Step 1 SETPOINT
Step 2 SETPOINT
Step 3 JUMPLOOP JS - 02 JC-01
Step 4 JUMPLOOP JS - 01 JC-01
Step 5 SETPOINT
Step 6 JUMPLOOP JS - 01 JC-01
Step 7 STOP
The steps in sequence will be: 1,2, 3,2,3,4,1, 2, 3,2,3,4,5,6,1,2,3,2,3,
4,1,2,3,2,3,4,5,6, 7.
Intertwined LOOP
An “Intertwined” loop can break across other loops.
Step 1 SETPOINT
Step 2 SETPOINT
Step 3 JUMPLOOP JS - 01 JC-01
Step 4 JUMPLOOP JS - 02 JC-01
Step 5 STOP
Rules to Follow
The one basic rule that you must follow is that you can only have a
maximum of three consecutive jump loops.
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
SETPOINT
JUMPLOOP JS-01 JC-01
JUMPLOOP JS-01 JC-01
JUMPLOOP JS-01 JC-01
JUMPLOOP JS-01 JC-01
STOP
Your program will run until it reaches Step 5, and you will receive an
ER2 0039. This is the infinite looping error, and means that you have too
many consecutive loops.
Another rule to follow is that you cannot JUMPLOOP to a step that you are on.
You will receive an ER2 0039. Clear the error in the ER2 parameter under the
SYSTEM menu and retransmit your data.
Use simple loops in your program!
How To Progam the Series 920, Chapter 6 WATLOW Series 920 User’s Manual 39