How to calculate network latency in a communication line with only Modicon switches (MCSESM & TCSESM) between source and destination?

The MCSESM has a latency of < 4 µs. However, for the TCSESM, the latency depends on the device. between 2 neighbor ports the latency is 2,7µs, and it can be up to 32µs (variant with high port number and communication from 1st to last port). Typically, it will be around 3-9µs.

Those numbers are all very small.

The switches are store and forward switches. This means they have to receive and read a whole packet until they start to send it out again. Therefore, depending on the packet size the delay per switch (and device) is about 5,12µs to 121,76µs for min. / max. packet size. This carries obviously more weight.

With these numbers you can calculate the delay of the network easily. Simply spoken - the less switches in a communication line the smaller the delay.

Gepubliceerd voor:Schneider Electric Belgium