CompactLogic with MVI69-MCM and mass flow meter (Emerson)

[anhkhoi]

Hi all,


I had trouble with commmunication between Mvi69 and mass flowmeter (micro motion-emerson).
I configured Mvi69 is master and mass flowmeter is slave using Rs485.
On mass flowmeters use floating point (2 registers 16 bits) for 1 data point. For example 0247-0248 for mass flowrate.
In Mvi card configured address for read this data point is 40248 (because of offset address is 40001).
but the data reading is not true, it jumped randomsly.
Data type on mvi69 is INT, so I not sure it can display floating point.

Anyone has experience on them? pls help me!

 

[Pudden]

Hi Anhkoi,

I have no experience with the MVI69, but have worked with several flow meters.
There are many Modbus RTU masters that do not support 32/64-bit registers.
If the master does not support 32/64-bit registers, you will need to use a gateway, such as:
http://www.anybus.com/support/support.asp?PID=317&ProductType=Anybus Communicator
The gateway can be configured to read any type of register from a slave and relay the data in "normal" 16-bit registers, to your Modbus master.

FYI, Modbus that uses 32/64-bit register is called Enron or Daniels Modbus.

Best regards

Patrick Lansdorf

 

[anhkhoi]

Thanks Patrick,

I cleared my issues already.
I did reading 32 bits floating point register (2 register 16bits) from slave device and after that copy these 2 registers to array Real type tag and it's scaled to 32 bits floating point data.