Modicon data sharing

Hi all,

Moving into a Modicon plc project- after not having used this flavor for a number of years.
My question...I will be using some interlock and control bits that will primarily be between a Quantum and Compact on a MB+ network and would like to know advantages/disadvantages, pros/cons of MSTR and Peer Cop. I've used MSTR in the past, but PC is also quick and easy to setup. The Modicon networking manual is vague to me.

Any info- even opinions- would be appreciated,

Mike

Quick and dirty answer.

MSTR blocks requires/allows you to manage the exchange of information.

Peer cop handles the exchange automatically. The data is conveyed as part of the Modbus Plus token. Peer cop allows dedicated (one to one) as well as global (everyone can see it) data exchnages.

Given the choice I would use Peer cop for continuous exchanges like I/O status and MSTR for infrequent data.

I agree with Jim - if you have a limited amount of data, and it is in contiguous blocks, peer cop is simple and fast and easy.