# Code Resources

A

#### Alex Pavloff

Hey folks. I'm taking on the task of making some general resources for people writing communication code, with the intent of putting this onto the PLC archive. I'm starting with Modbus, so I've been looking around for all the Modbus info on the web. Modbus has a lot of information available -- a couple order of magnitudes more that every other protocol I typed in, so I can cull the info to come up with the "best of the web" modbus page. The first place to look is: "http://www.modbus.org/":http://www.modbus.org , and they have a fairly complete FAQ on Modbus TCP. No info on Modbus ASCII, Modbus RTU, or Modbus+... The protocol is very similar of course, but they don't say that. There are many links there I did manage to find a VB program that does Modbus, with some other useful links at "http://members.tripod.com/~mbserver/":http://members.tripod.com/~mbserver/ . So the first question is -- does anyone else know of any good links to Modbus resources that would be worth putting on a FAQ page? The second question is -- what other questions should be answered in a pan-Modbus FAQ? And the third question after that is... what other protocols would people like to see a FAQ/resource list for? I'm working in a nearly 100% serial world here, and so I'm not familiar with other fancy-schmancy wiring schemes companies have cooked up, and so I'm going to list the protocols that I know, and that I think should be looked at (in no order of significance whatsoever): Omron Hostlink Allen Bradley DF1/DH+/DH-485 GE-Fanuc SNP and SNPX Aromat MEWTOCOL-COL Seimen's MPI Koyo Directnet Mitsubishi FX Series (the exact name of protocol escapes me at the moment)

Thanks for any response:

Alex Pavloff
Software Engineer
Eason Technology

B

C

#### CK

Your comment is confusing. Modbus is an OPEN protocol, and you said you wouldn't waste your time on the 'proprietary protocols'... Modbus is open, the protocol is available for download from Modicon, and it's supported by a large number of third party devices. Modbus would be an ideal protocol to implement for basic serial communications due to it's large supported base.

CK

A