Modicon Quantum programming Unity


Thread Starter


Hi all,

I have a question regarding the Modicon Quantum and the programming software Unity. I have a new work where the factory is controlled by Quantum PLC.

My question is: Is is possible to program the PLC online from 2 different places at a time. I experienced this capability on the ControlLogix from Allen Bradley and I would like to know if we're able to do the same with Unity. Is there a special version that we have to buy to do it ?

Thank you taking of your time to answer me.

Schneider Italy

No it isn't. One user at a time. If another one tried to connect, Unity would advise that the PLC is reserved and would permit only to view and control variables in a template.
Why on earth would you want this feature? this can be very dangerous. What if two people are changing the same set of code at the same time?
The answer is NO. ONLY ONE USER AT A TIME!!

Also, I wonder how could somone be in 2 places at the same time, trying to programme A single PLC!!

Do you understand how dangerous this could be and what consequences it may lead to?

Please weigh up what you have just said .. a QUANTUM PLC controlling a FACTORY. What possibly could happen to the factory if something goes wrong while 2 people are trying to programme this PLC online!!!!!!!!!!!! Right, this is not a toy.

I really have no comment on this one, except "the more one lives the more one sees and hears".

Good Luck.

Hmmm...I am hoping that you meant that you want to have the ability to program the Quantum from either one of two locations because as everyone else here said you can't and should not want to do it simultaneously.

If what you want is two options such as a remote and a local location then you could easily achieve this via your Ethernet port (on your NOE card). But here's the thing you would have to switch the port so that either your local or remote PC is the programming device. Also (by assuming that your remote location is accessed by a network) you would also need to have two different cables (i.e. straight for network and crossover for direct). And then even if you have all the infrastructure required in place you need to ensure that the two PCs ALWAYS have the latest version of the program that matches the PLC so as you make changes on one and save you have to then go and copy that saved program onto the other PC. This will ensure that you are not locked out of the PLC with an old version of the program on your PC.
I hope this is a misunderstanding and that you mean if you can program the PLC from 2 different locations (not at the same time). This of course is a resounding yes. save your PLC programs on an accessible network location (i.e. same server as where your SCADA system resides).

If you did mean to program the PLC simultaneously from 2 different locations/people than everyone else is correct... Don't do it, stay away.

the memory structure is different than the Rockwell system, because the Modicon program compiles the logic in a way that 2 person access is unallowed.
If you connected the NOE or the Processor Enet port to a switch (Yes you can program via the processor and/or an NOE module) then one cable to the switch will do. Then the switch can connect to whatever.

If you have configured the Unity project for upload, then you can upload/edit/save changes to the plc and other users can do the same to stay equal.

A current version of Unity will work with older project versions and firmware in controllers. It is not necessary to update the processor firmware every time you update the software. Unity V4.1 will connect/edit a V3 project and leave it as a V3 project. The option exists to remain or update.