Compact 984


Thread Starter

Walt Flannigan

I'm evaluating a plant using these...they comprise 10% of the PLCs on site, the rest are A-B SLC/MLogix. It makes sense to convert to align, but I'm looking for some info on availability, etc. I didn't have much luck on Schneider's site.
Is is true that the Modicon Compact is no longer in production (Obsolete is such a tacky word). However, some distributors in Canada and the USA still have stock. Schneider Services is also a good source for parts. In Canada and the USA there are migration paths and procedures that can move you to the Modicon M340 platform. This will save you the large labour costs of re-writing the projects. The M340 will be able to communicate easily on the plant LAN with its in rack support of EtherNet IP.

Rather that going to a web site, call your local office. Can't find one? Email me at brian.cervi[at] and I will locate one for you.

Ronald Baggett

The M340 does have ethernet, but does not support modbus plus. I did not see where you mentioned the communication fieldbus used. What programming software do you have access? Software costs can be a consideration, especially with AB products. We are no longer using the AB SLC PLC's. We are using compact and control logix for the complex solutions. The micrologix 1100, 1400, and 1500 are our choices for less complex solutions. We use the M340 wherever we need a Modicon platform. The Unity Software required is well liked. IMHO AB tech support is a bit better, but AB can be a pain with regards to costs and licenses. For very simple solutions, the SR3 smart relay is a great choice.
Regarding the Modicon M340 PLC and Modbus Plus. It is true that the M340 does not have a MBPlus connection on the controller but MBPlus can easily be achieved using the Proxy Module (TCSEGDB23F24FA). The M340 "side" of the proxy module is Ethernet (network). Proxy makes the M340 look and function like a typical MBPlus node.