Modbus Slave Device not giving stable data to ES

[vihanger]

I am trying to get data from the following flow meter.

and this is the modbus register list I was provided with.

I am getting values when I connected the flow meter directly to a USB to RS485 converter.

But when the flow meter is connected to my ES, I am not getting stable data.

What could be the cause for this?

All the data are in this link : FLOW METER ISSUE

[Charles_Murison]

Hello Vihanger,

For modbus serial communications, there could be a few things happening. On the RS-485 side of things, perhaps you need to bias the serial loop. Example https://commons.wikimedia.org/wiki/File:Rs485-bias-termination.svg. 

From the modbus side, perhaps you are requesting data faster than the flow meter can handle.

Regards,

Charles

[vihanger · Accepted solution]

Thank you for the reply!

However, the issue has been solved!

The issue was that the register I needed to read was in float 32bit type. I had to extract the register using 16bit points and bit masks as four different points and then write a script to merge those four extracted points into one float point.