schmersal Praxi 100, Manual

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It is possible to open up to three Modbus TCP/UDP connections to the Praxi 100 family AC drive. One of the connections
could be used for process data and other just for reading monitoring data. In most cases it is desirable that if “monitor”
connection gets disconnected, no fault is generated but when the connection is handling the process data, a fault
should be generated in the time specified.
This register address enables the user to give custom communication timeout for each connection. If a custom timeout
value is used, it must be given every time a connection is opened. Timeout can be set only to the connection which is been
used to access this register. By default the connection uses the communication timeout value given via panel parameters.
If the cable is disconnected, a fieldbus fault is activated after the timeout period. When communication timeout is zero,
no fault is activated.
In Modbus RTU you can only have one connection, so there is no need to use this value.
Table 35. Communication timeout register
Figure 8. The Molbus TCP/UDP function in case of timeout
Communicating
Check Yes
No
Yes
Closed
Yes
No
Broken
No
Received
packet during
communication
timout time?
Timeout
Communication timeout zero?
Connection closed or broken?
Has second connection with
communication timeout
other than zero?
FAULT!
No Fault
Holding register address Purpose Description
40501 Communication timeout
Connection timeout value for this
connection in seconds.
6.4 Modbus TCP/UDP Communication and Connection Timeout