MODBUS RTU communication time out faillure

[dalllelmouez]

Good morning,

We are trying to build a data acquisition app with ignition before to bye a license, we get a problem of communication with MODBUS RTU module,
we have 3 Modbus address of flow meters when I communicate with only one I don’t found any problem , when I enter the second and the third flow meters I got a problem of time out
could anyone help me to resolve this issue?

[Matrix_Engineering]

You might get some ideas here:

Modbus rtu over tcp read failure

Your network load is not the problem. Based on your JSON export, most of your tags are contiguous, words 22-35, with three others: 6-7, 44-45, and 66-67. Ideally, you need four requests to read these blocks, satisfying the ten float tags. Per the modbus specification (PI-MBUS-300 from modbus.org) these requests and their responses should take 62.5ms at 19200-N-8-1 (including the inter-message silent time on the wire). Twenty devices is a modest overload–you won’t get one-second timing. I be…