Program change alarm in 800xa
Hello,
Is there a way to trigger an alarm in case of a program change in any time on AC800?
Thanks,
Is there a way to trigger an alarm in case of a program change in any time on AC800?
Thanks,
Asked 2 months ago
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4
This is an inspiring question. I have 2 ideas.
1. During downloading to AC800M application stops for at least 100ms. Stopping time depends on how many retain variables are in your Application. Complex applications may stop for 300ms or more.
I think it is possible to build a simple logic running in fast 50ms task , which can compare current system time in millisecond precision with memorized time from previous program cycle.
AlarmCond FB input should be activated if time difference is greater than preset limit for example 80ms . In theory it should work.
2. Easier option : use a local bool variable without Retain attribute and without Initial value. After downloading this Boolean must be zero. Connect this *inverted* variable to the input of AlarmCond FB. Insert next FB SetTrue and connect its output to the same Bool variable.
1. During downloading to AC800M application stops for at least 100ms. Stopping time depends on how many retain variables are in your Application. Complex applications may stop for 300ms or more.
I think it is possible to build a simple logic running in fast 50ms task , which can compare current system time in millisecond precision with memorized time from previous program cycle.
AlarmCond FB input should be activated if time difference is greater than preset limit for example 80ms . In theory it should work.
2. Easier option : use a local bool variable without Retain attribute and without Initial value. After downloading this Boolean must be zero. Connect this *inverted* variable to the input of AlarmCond FB. Insert next FB SetTrue and connect its output to the same Bool variable.
Answered 2 months ago
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