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Connecting PLCs?

Connecting PLCs?

Connecting PLCs?

How do we connect AB SLC5/04 PLCs using a data highway cable so that they communicate with each other.
Teh actual problem we have is we have a motor controlled with a plc. Now we have another plc in another location. How do we connect these two plcs using a data high way cables and control the motor with the second PLC in another room. we also have a rsview software available that should be used

RE: Connecting PLCs?

Use extreme caution.  you can control one slc from another slc, but I would not recommend it.  Why do you want to do this in the first place?  What do you hope to accomplish?  How about a panelview or another HMI.  A little more information would be helpful.


RE: Connecting PLCs?

Provided both PLC has DH+ connection, you can tranfer information between the two PLC by writing some programs. You have to think about how the software will react in the event that the master PLC controlling the motor fails. Once you have these requirements you can design the software to work accordingly.

Having said that, I still wonder about your application and why you need to do what you are saying. Wouldn't it be easy to control the motor directly from the same PLC it is connected to? Plus you have rsview. You can do wonderful things with that to control both PLCs.


RE: Connecting PLCs?

we are trying to control the motor from a different location. so we willbe needing to connect two PLCs one close to the motor and the other at a different location. we need to establish communication between the PLCs. One PLC(located away from the motor) has the access to RSView.
So using DH+ how do we configure the PLCs?   

RE: Connecting PLCs?

Make sure both PLC’s have DH+ such as a slc50/4 then cable them with your blue hose, if not already done so. And of course you will need different ID in each PLC. Also the Data rates must all be the same in all devices.
Now in your logic setup an MSR block in you PLC that has the motor connected to it. Set the MSG block as a read. I suggest putting it here because you then can monitor the MSG block for error and take appropriate action with the motor. Such as in cases where the remote PLC is not available you could stop the motor.

I would suggest reading more registers than required incase more control is required later.

With out knowing your setup better that is all I can say.

This should be rather simple.

What PLC do you have? PLC-5, PLC-2, SLC50/4 ect.
What programming software do you have? Logics, A.I. Icom ect.

RE: Connecting PLCs?

The PLCs we have are PLC-5. The software we have to use is RS-view. we have RSLogix, RSView nad also Visio. The plc5 taht is connected to the motor is up and running. All we need to do is run a DH+ cable from another plc ( Say plc2) that is connected to a computer that has rsview on it and control the motor that is connected to plc1. Can anyone give me a step by step procedure how to get this done. The PLCs, the computers and the DH+ cable are all in place. We need instructions on
1. how to make the PLCs talk to each other and
2. How to program RS View( Cause we donno anything about programming RSView.)

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