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What is the minimum refreshment period for IFM's stacked to one IFE server?

Issue:
Possible comms loss due to polling too fast

Product Line:
Circuit Breakers

Environment:
Breaker digital systems IFM  IFE server

Resolution:

Connect intelligent modular units to the Modbus network with the IFM Modbus-SL interface for one circuit breaker.

The 24 Vdc power supply terminal block delivered with the IFM interface is used to supply the IFM interface with power either in a daisy-chain or in a star connection.

In terms of power supply, the maximum number of IFM interfaces stacked to one IFE server is 11 in order to limit voltage drop.

In terms of Modbus communication, it depends on the performance requirement. As it takes approximately 500 ms at 19,200 Baud per device to refresh 100 registers, the more interfaces added the longer the minimum refreshment period. The minimum refreshment period depends on the number of IFM interfaces stacked to one IFE server. Multiply the time to refresh one device by the number of devices to find the minimum refreshment period expected in the application. For instance, an installation with eight IFM interfaces stacked to one IFE server at 19,200 Baud would take approximately 4 seconds to be read.
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