Communication between BSAP-MODBUS


Thread Starter

Jorge Muñoz


Dear Friends.
We are looking for device that permit us to use our MODBUS RTUS or MODBUS PLUS network to communicate with a SCADA system that has a BSAP (Bristol serial protocol) as their native protocol. We have a network with some MODICON (Quantum series) devices and now we must connect this network with SCADA system that is working with a RTU Bristol ( Series 3000 ) by radio signals.

Thanks in advance for your help

Jorge Muñoz
[email protected]

Robert Dusza


I don't think there is a device that converts form MODBUS to BSAP. MODBUS RTU is built into the Series 3000 RTUs. You have a few ways to accomplish the transition:

1) You can program a Bristol RTU to run MODBUS on one port and transfer the data to the System 3000 via another port. Use it as a protocol converter.

2) Convert the System 3000 RTUs to talk MODBUS on the radio links, instead of BSAP (probably not he best way to go if you have a large number of BSAP Nodes).

3) Use OPC to transfer data from the MODBUS or BSAP networks to the other protocol.

Any way you do it, it won't be easy. We use the System 3000 with iFIX as the GUI for our water system. BSAP can be a real pain, no one in the
converter side of things has a driver for it that I can find on the web.

Let me know if you find anything and how you make out with the project.

Hope this helps,


Robert J. Dusza, Jr.
Project & Technical Support Manager
(V) 1-860-647-3219
(F) 1-860-647-3150
E-mail - [email protected]
Manchester Water & Sewer Dept.
125 Spring St. P.O. Box 191
Manchester, CT 06045-0191

Mark Headley


We have developed a Momentum processor with BSAP Slave with a read/write lists. Write now its is used to accommodate a combo I/O module. We use it for smaller sites and will be using is to migrate from BSAP to Modbus. If you are interested, please feel free to contact me.::

Mark Headley
Pro-Tech Engineering
[email protected]

Jorge Muñoz

Robert, Thanks for your information.

When we have more information about it We can send you.

Thanks in advance for your help.

Jorge Muñoz