Profibus and different brand PLC's

Hello

I have a situation where I need to connect a Mitsubishi Q PLC and a Siemens Simotion PLC. The Siemens will be using Profibus to control several Drives. I would like to know if it is possible connect to the Q series with a Profibus coms module.
I need to pass start/stop, speed up/down, speed value, and drive condition info between the 2 PLC's

Can I use Profi with 1 as master the other slave or will I need to use IO

You may be able to setup 1 PLC as a master and one as a slave. We do this with our S7-300 and 400 series sometimes when they are communicating with S7-200s.
Another way is to get a Profibus coupler. In this case, you would setup 2 networks, with each PLC as the master of its own network. The coupler would act as a slave on each network, with an addess for each network. It would then simply couple the IO between the PLCs. i.e. the outputs from one PLC would appear as inputs on the other, and vice versa. I have been eyeing off some siemens couplers for some time, trying to find a use for them. You can pass data as either bit, byte, or word. I believe double word is also possible, but I haven't checked recently. I believe the maximum data that can be transferred is 240 bytes either way.

Have a look at the q series QJ71PB93D module which is a profibus slave or QJ71PB92D Profibus master.

more info here:
http://mitsubishi-automation-resource-mirror.de/resources/technical/136730.pdf
Section 5 - Profibus

Thank you

The Q can definately be the slave with the QJ71PB93D if the Siemens is the master. No problems.

If both need to be masters - in the event that you are running 2 networks, Siemens makes a Profibus coupler that allows the 2 master to exchange data