With the "Pulse counting” function, pulses arriving at the binary input can be recorded, counted and saved. It is possible to count in the positive as well as in the negative direction.
The prerequisite for this function is that the "Single” option is selected in the device settings for the channel concerned.
“Function of channels A + B” parameter
This parameter can be used to set whether the counter reading is increased with a rising and/or falling signal edge.
The counter reading is stored in the communication object "A Count” (20) and can be sent on request or automatically after a change by a certain value or cyclically, depending on the configuration.
Via the communication object "A Count” (18) the counter reading can be reset to the value "0” or another value by telegram if required.
Optionally, a limit value and monitoring of the limit value can be configured. Exceeding or, in the case of negative counting, falling below the limit value immediately results in a logical 1 being sent via the communication object "A Above limit” or "A Below limit." The limit value can either be specified via the parameter "Threshold” or changed via the communication object "A Threshold” by telegram. It is also possible to query the limit value via this communication object. If the limit value is undercut again by resetting the counter reading or by changing the limit value, or if it is exceeded again in the case of a negative count, this immediately results in a logical “0” being sent, since the counter reading is again in the permitted range.
If the supply voltage for the electronics fails (bus voltage failure), the counter reading and also the limit value are permanently stored in a memory protected against data loss in the event of a voltage failure and are transferred from this memory back to the main memory when the bus voltage returns.
Application example
Access control:
Only a certain number of people are allowed through, then access is blocked for a certain time.
One use case would be, for example, access to the elevator in the TV tower or access to an area where not too many people are allowed to enter at the same time.