Behavior At The Counting Limits - Siemens Simatic ET 200SP Equipment Manual

4.7

Behavior at the counting limits

"Reaction to violation of a counting limit" selections are defined as follows:
• "Continue counting": After a violation of a counting limit, counting surpasses the limit
and goes to either the start value or the opposite counting limit (depending upon
configuration), and then continues.
• "Stop counting": After a violation of a counting limit, counting surpasses the limit and
goes to either the start value or the opposite counting limit (depending upon
configuration), and then stops. To restart counting, the SW gate must be closed and
reopened.
The "Stop counting" selection may not allow the module to react at counting limits.
Configuring the "Reaction to violation of a counting limit" selection to stop counting may
have a direct and detrimental influence upon configured safety monitoring and measured
value.
You must ensure your safety program has provisions for the immediate stopping of
counting and any potential influence upon configured safety monitoring functions and
measured value.
Violation of a counting limit
The high counting limit is violated when the current counter value is equal to the high
counting limit and another up-count is received. The low counting limit is violated when the
current counter value is equal to the low counting limit and another down-count is received.
The appropriate status bit is set in the feedback interface in the event of limit violation:
Counting limit violated
High counting limit
Low counting limit
You can reset the status bits with "Reset Other Events" bit.
Following a counting limit violation, you can configure whether counting is to continue and
whether counting is continued at the start value or at the opposite counting limit.
Note
The high and low counting limits define the value range of the counter.
ET 200SP F-TM Count 1x1Vpp sin/cos HF (6ES7136-6CB00-0CA0)
Equipment Manual, V1.0, 01/2021, A5E47073911-AA
WARNING
Parameters/address space
4.7 Behavior at the counting limits
Status bit
"Overflow Event" bit is set
"Underflow Event" bit is set
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