Improve Performance On Reading Speed Modbus TCP Protocol

Marx_00 · ‎11-16-2022

Hi all,

I'm trying to develop a DAQ application using the Modbus TCP protocol to comunicate with a PLC.

The DAQ write a value on an input register address and read the same input register and the following one (function code 4).

The system need to sample te response reading the input register with a sample rate of at least 100Hz. Unfortunately I can't go over 35 reads per second.

I've tried implementing a small test VI opening the Modbus connection, reading in a loop and close the connection in the end.

The PLC should have a cycle time of about 1ms.

I've tried different API's downloaded from the VI Package manager and different labVIEW versions (2017 SP1 and 2022 Q3) but the result is exactly the same.

Is there any way to improve the execution speed of the reading section?

I'm still a beginner in LabVIEW, so I would not be surprised if it is a easy problem or a stupid error.

Thanks!

Marx