DH485 Network and Multiple PCs

[GenII]

I am attempting to configure a new PLC network. So far my configuration is as follows:

6 x SLC 5/03 racks
6 x 1746-AIC isolated couplers
6 x PCs (windows XP) connected via 1746-UICs, each running RSLinx, RSEmulate, RSLogix 500 and RSView32

I can get the PLCs networked with one PLC. However, as soon as I connect another PC the network loses connectivity sporadically with the nodes. I realise that this type of network is primarily used to network several PLCs with one PC but even RAs site shows a typical configuration that contains more than one PC.

Is there any way that I can have the PCs connected all at once without any conflicts? I am trying to configure it so that any PC can program any of the PLCs.

 

[bernie_carlton]

Probably obvious but - make sure all the station numbers, including the PCs are unique and below 32.

 

[GenII]

Probably obvious but - make sure all the station numbers, including the PCs are unique and below 32.

Thanks for your quick reply, I have made sure that each node has a separate number and are under 32. I have double checked the connections, but with no luck!. Hey, even if you think it is obvious, please state it, I need all the help I can get!

 

[ianingram]

I am attempting to configure a new PLC network. So far my configuration is as follows:

6 x SLC 5/03 racks
6 x 1746-AIC isolated couplers
6 x PCs (windows XP) connected via 1746-UICs, each running RSLinx, RSEmulate, RSLogix 500 and RSView32



Is there any way that I can have the PCs connected all at once without any conflicts? I am trying to configure it so that any PC can program any of the PLCs.

Hi

The following is a copy & paste from a technote;

44717 - How to use the 1747-UIC device and driver to change between processors.

How to use the 1747-UIC device and driver to change between processors.



Assuming the 1747-UIC device is already in use with a processor, the user wants to disconnect the 1747-UIC from this particular processor and directly connect to a different processor.

1. With the driver still running and the 1747-UIC still connected to the first processor, go to RSLinx, Communications, Configure Drivers, click once the on the 1747-UIC driver, then select the STOP button on the right side of the screen. If it cannot be stopped, make sure any RSWho screens in RSLinx are closed.

2. With the driver stopped, disconnect the communication cable from the processor and connect it to the new processor.

3. In RSLinx, Communications, Configure Drivers, click once the on the 1747-UIC driver, then select the START button on the right side of the screen. The driver should display 'Running'.

Note: If the driver is running and the cable is disconnected from the processor, the driver will lock up. In order to get the communications working again, the existing driver will need to be deleted and a new driver created with the communications cable connected to a processor.

Let me start by saying that I have not had any experience with the 1747-UIC, but my experience with DH-485 is that it is not a great, stable network...it is a bit dated now...


By reading the above, each time you want to make a program change to a PLC, you will have to set up the driver..noticing that you want any PC to program any PLC...

So there would not be any benefit to having a PC connected to a PLC all of the time...I wouldn't recommend doing online edits on more than one PLC at a time with this type of network.

Hope this helps..I am interested to hear what others have to say on this issue.

 

[bernie_carlton]

I think he's trying to set up a network where the PCs are always physically connected to the network.

The UIC DH-485 station number is set on the UIC itself. If that is proper on each one and thaty have power through their USB connection they should be good neighbors on the network. Re-check the connections.

 

[Mickey]

You are pushing the limits of a DH485 network.
But here is a shot in the dark that sometimes helps,try unchecking the "Autobrowse" in RSLinx after communication has been established.

 

[bernie_carlton]

Re-check that you can have multiple UICs on a DH485 network. Even without setting up a link you should be able to connect the powered up UICs to a network (assuming unique IDs) without disrupting the network itself (except for the momentary token-passing reconfiguration).

 

[GenII]

Thank you all for your replies. I will try these out tomorrow and let you know how I got on. You are absolutely correct, I wanted to leave the PCs connected permanently, but I have a fear that I won't be able to.

Once again, thank you for your replies.

 

[OkiePC]

I agree with Mickey that you are pushing the limits. One thing that may help is to use all consecutive node numbers (don't skip any), and limit the maximum node address in the channel configurations of all devices to the highest number that is actually in use.

I have worked on a DH485 netowrk with 9 nodes that was kinda slow, and became painfully slow when we had to add a PC as the tenth node.

Paul

 

[James Mcquade]

You will need 12 link couplers.
the extra 6 are for the pc links.
what you are doing is adding another connection point to your network. this is a a daisy chain link and the pc's are escentially another connection point and require a coupler of their own.
you will also have the problem you described if you connect
2 or more pc's to the same plc's when you do on line edits.

I had the samp problem years ago with my network.
Check with your local rep and discuss with hom.

regards,
james

 

[GenII]

Just a little update.

Firstly, thank you to all who contributed, unfortunately, I haven't had a chance to try this out properly as we are now experiencing problems with our software. Hopefully this will be getting sorted out asap.

If I get a solution to my problem, I will update this thread with the answer.

Best regards,

GenII