Logging of data at defered lagging time in MODBUS network

  • Thread starter R.K.Roy.Choudhury
  • Start date

Thread Starter


I have connected 18 instruments with RS 485 MODBUS, Half duplex fashion. We are using FTDI V2 RS485-USB converter. In my application the PC (with Core i3 processor and 4 GB RAM) is the MASTER. We are using a Data Acquisition software. We can view the reading against of all the devices and devices are On-Line. Our Set Logging Interval is 10 Minutes.

We have noticed that after running of 24 hours the data has been logged against the devices but with 8 - 10 hours lagging time. That is, if the present time is 11.00 AM 31-05-2013, the data has been logged with time (around) 9.00 P.M. 30-05-2013.

Can anybody help us to resolve the matter?


Dear Sir,

Thanks for the advice. But what is ZULU time. Can you please explain me,so that i can identify the issue .

With Best Regards

Lynn August Linse

>We are using a Data Acquisition software.

Sounds like a bug in the "Data Acquisition software", so ask them. Since Modbus doesn't have any time or timestamps, it's not a Modbus problem.