Watlow Series 922 - Manual (Page 19)

Sample Program, Chapter 3
WATLOW Series 922 User's Manual
19
Sample Program
WHR, WMN, WE and W1 are unprogrammed. To program a WAITFOR time,
enter your values for WHR and WMN. The programmed WAITFOR time waits
until the specified amount of time has elapsed. WAITFOR time (WHR, WMN),
WE, and Channel 1 process variable (W1) can be programmed simultaneously.
Each of these Wait For conditions must be met before the program will con-
tinue. Once a WAITFOR condition is satisfied it latches, and does not have to
be performed again.
Run your program from FILE 5, STEP 1. If you do not want to go through the
entire program, you can START your program at any STEP in FILE 1 or 5.
When your program reaches FILE 5, STEP 6, the HOLD LED begins flashing.
This means your program is still running, but it is HOLDing, to WAITFOR the
ACTUAL temperature to equal the WAITFOR Channel 1 (W1). When they are
equal, the HOLD LED stops flashing. Your program continues to the last step,
a STOP step, and HOLDs again. In the HOLD mode the Series 922 controls
the process to the set points of the last SP step.
If you want to change a programmed step, return to the PROGRAM menu, and
enter the FILE and STEP number you want changed. Use the UP/DOWN keys
to select another step type and press ENTER.
To clear all parameters under a step type of its programmed values, return to
that step type and press ENTER. All parameters return to their defaults.
FILE STEP STEP W1 WHR WMN WE
TYPE
5 6 WAITFOR - - - -
5 7 STOP
Table 6 -
The WAITFOR Step
The WAITFOR Step
The last step type we will work with is the WAITFOR step. This is a test step.
It compares a specified temperature with the process temperature, or a speci-
fied event state with the event input, before continuing the program. It can also
wait for a programmed time to elapse before continuing on with the program.
After the test is successful, the program continues with the next sequential
step. Events cannot be programmed in this step; they maintain their previous
state.
Return to PROGRAM and enter FILE? (5). Add a WAITFOR step to the end of
that file.