Purpose
Waits for a preceding WAITFOR or WAITSTAT command to timeout before proceeding to a step number other than the one that follows either command.
Syntax
IFTIME GOTO step#
Example
Use the following example, to provide a processing check:
|
Step |
Command |
Action |
|
08 |
MAXWAIT 60 |
Set the maximum wait time. |
|
09 |
WAITFOR AI1 > 90 |
Wait for the temperature to exceed 90 degrees. |
|
10 |
IFTIME GOTO 14 |
If the temperature is not greater than 90 degrees after 60 seconds, go to step 14; otherwise, proceed to the next step. |
|
11 |
MAXWAIT 0 |
Reset MAXWAIT before making a call. |
|
12 |
CALL PROCESS |
Call a Program block that runs the actual process. |
|
13 |
END |
End the program. |
|
14 |
CALL WARMUP |
Call a Program block that increases the temperature. |
|
15 |
GOTO 8 |
Return to step 8. |
NOTE: In this example, the MAXWAIT command determines how long the block waits for the temperature to exceed 90. Yet whether the process times out or the condition set by WAITFOR is fulfilled, the block continues to the next step. This means that in the event of an equipment failure another process operation is executed in response to the failure.
By including the IFTIME GOTO command, you provide an alternative path if the WAITFOR condition is not fulfilled.
