Can OMNI flow computer communicate with Delta V system?


Thread Starter

Nelson Yañez

I need to connect 8 OMNI flow computers with a Delta V system and I don't find a modbus interface with the system.


Delta V system do have Modbus interface both
Master/slave mode.Your omni computor should have
Modbus RTU protocol [ slave ].

Rather than using a flow computer that uses Modbus communication, why not go for a modern unit that uses FOUNDATION(tm) Fieldbus? We (SMAR) make such flow computer. It uses FOUNDATION(tm) Fieldbus H1 to connect to the field instruments, and FOUNDATION(tm) Fieldbus HSE (Ethernet and IP) to connect to the host computer (configuration tool and central logging archive). Using this architecture I believe you will get a more powerful solution. You can remotely diagnose and parameterize your instrument. The flow computer audit trail also logs changes made to the field instruments etc. This is a level of functionality not found in earlier flow computers. Kindly contact me directly on the below address.

To understand the advantages of FOUNDATION(tm) Fieldbus HSE (Ethernet and IP) as an open system control network and, how to build wireless SCADA if you have to, take a look at the book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance" (buy online in hardcopy or download immediately in softcopy). If your email does not support this hyperlink feature correctly, please copy the URL and paste it into your Internet browser. Mind the line wrap, make sure to get the complete path all the way to the 3036: Display.cfm&ProductID=3036

If you can't buy the book now, you can download chapter 1 (overview) for free in softcopy form. It's free, but you must register an account. Mind the line wrap, make sure to get the complete path all the way to the 4585: Display.cfm&ProductID=4585

Jonas SMAR [email protected]

As for the Omni, the serial interface card is required (and has to be set up) for Modbus interface. Depending on where the serial card is placed, the connection is made on the terminals at the rear of the enclosure.

Rockwell Hardware/Software Solutions
for Western Canada and the World

Mark Hensley (Kepware)

Hi Nelson,

Our Modbus RTU serial driver has exstensive support for the OMNI Flow meter. Delta V is an OPC enabled system. You should be able to use an OPC server to gather the data.

Here is a link to our Modbus RTU server.

If you have the time, download the demo version which will provide the full help file and complete details on the support of the OMNI Flow meters. You then be able to try out the Modbus RTU server directly with the OMNI Flow meter.
I think the easies thing to do is to get a DeltaV serial interface (Serial card). This has two serial ports and communicates with at least 16 devices (500DSTs OR 3200SCADA). Supports modbus just fine. Get in contact with emerson for details.
Yes. You will need Enron Modbus driver from Mynah ( and a serial card from Delta V to communicate the OMNI to the Delta V.

We did this many times and it works without problems. Be careful to buy the correct driver version. If your Delta V serial card is 1 buy the driver version 1 and if it is 2, buy the version 2.
Delta-V is an OPC Client. There are several vendors providing OPC Servers that have very well integrated communications with Omni flow computers. KepWare is one and another is Automation Solutions ( ).

The advantage of an OPC server is that it can interfaced to many different end devices simultaneously such as PLCs and flow computers. Actual communications can used many different types of media such as Ethernet, Wireless, RS232 and RS485. The OPC server can also provide data to multiple OPC clients such as HMIs, DCS, Leak detection systems, accounting systems, many of which want the same basic data.

I am most familier with the Automation Solutions OPC server... this product can access all of the Omni's various resources such as real-time registers of all types, text reports, and hourly/ daily/batch archived data.

Requests for Reports and Archived data within the Omni are interleaved with the normal requests for realtime data making the retrieval process transparent to the client application.

Archive data will be populated automatically into almost any commercially available database type (SQL, Oracle, Access etc. etc).

Fieldbus solutions for devices such as high end flow computers containing upward of 20,000 data points and thousands of archive, audit, and report records is not a practical solution right now as I see it. Fieldbus is more suited to field devices such as transmitters and analyzers.

If and when we add it to our flow computers it will probably used to communicate with these types of devices, not the HMIs.