comparison

Distributor discounts and such vary - the best way to compare is put together an I/O list and a description of product requirements and get quotes from your local distributors for the system. They should be willing to come in and do a demo for you, so you can see the software and hardware.

I prefer A-B to Modicon. They each have their strength, but I find Concept software has a poorer interface than RSLogix, and the modules are not well integrated, and you have to more setup work. The 984 scanning is not intuitive, and the IEC logic takes some getting used to.

Why are you limiting yourself to these two brands?

My thought is that you are comparing an apple with an orange.

The 984 family is now a quite old Modicon product, of a similar age to AB's PLC5, and was a similar match in functionality.

By contrast the MicroLogix 1500 was released in the mid 90''s as a small low cost expandable "OEM brick".

Although the Micro 1500 is quite useful, it offers limited comms options ( 2 serial ports, and a DeviceNet scanner), only two memory sizes, limited max I/O (about 16 modules I think), and no online editing. Now this may be just fine for a smaller application, but if you are comparing with a mid-large sized application that the 984 could tackle, then the limits of the Micro will be a show stopper.

A fairer comparison would be between a Modicon 984 and the larger SLC500 processors (5/05,4, or 3) or indeed I would be seriously considering either ControlLogix or a CompactLogix depending on the size and nature of the application.

And to be fair Modicon offer newer systems than the 984. So all up I too am curious why you are making the comparsion between just these two PLC's.

Who has no on-line edit