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knowledgeconsumer (Industrial) (OP)
19 Sep 06 5:57
Hi Guys, im adding four extra nodes to my controlnet network. theres currently 25 nodes and 5 PLC 580's on it at present. my question is this, is it ok to just disconnect the last point in the link(node 25) and add these extra four nodes on the link and then reconnectup and replace the endof line resistor into the new endof line component(nodenode 29) ? is there anything i should be aware of or should be taking into consideration ?

the plant area will be sealed off and no devices active or production running. i will be merging all new io into one plc, therefore keeping the other plc's in run mode.


i need an urgent responce as i have to do this soon .. ! tanx in advance
NWBeaver (Electrical)
20 Sep 06 11:35
There are a couple of things you need to be aware of.
First, when you alter the network, by adding nodes, you will need to re-schedule the network, using RSNetWorx for ControlNet.

The second thing is the number of connections, which is not the same as the number of nodes. You can have up to 99 nodes, but the number of connections or devices is dependent on the type of hardware you are using.  This should be checked before you install the nodes.

If you are not familiar with any of this, you should call your local AB rep and have them help you.
knowledgeconsumer (Industrial) (OP)
21 Sep 06 5:00
tanx for the feedback,
im aware of the networx nessesity for configuring.im not going to reschedule the whole network because changes only affect one plc so ill only place that one plc in program mode, leave the rest in run and merge the controlnet changes when im finished.
what i need to know is this, is it ok to just dissconnect the last node on the link when gateway is running, will there be any affect, and when i reconnect the new nodes(in same panel)should i be aware of anything at this point ? basically i dont want to affect the rest of the link when i connect the new nodes.
NWBeaver (Electrical)
21 Sep 06 11:46
Assuming that you don't have any node address conflicts, I don't know of any problems you might have, other than perhaps some errors while the terminating resistor is removed.
djs (Electrical)
25 Sep 06 13:19
Be careful: Usually you will have to place all processors connect3ed to a ControlNet into program mode in order to reschedule it.

You might loss communications, or have a high error rate while you are making the connections. Unterminated network.
knowledgeconsumer (Industrial) (OP)
25 Sep 06 15:08
here's what happened when making the changes....
i connected the extra nodes onto the network, disconneting the endof line resister didnt cause any problems. I placed the PLC 5 that the IO was exclusive to in program mode, left the rest in run.
Went online to controlnet with version 7, configured the nodes and went to merge the change. The software hung on me and 15 minutes later i had to end task the controlnet to get out of it. After that when i went back online,all devices had extra as a status and network wouldnt let me optimize and re-sched as it didnt see an active keeper!only thing to do was re-download my backup and get the network back to its original state, placing all plc's in program mode to do it.
When i browsed the network, the additional nodes were not seen but were still in the plc's scanlist config, great. Rescheduled the network and all was ok.
I wonder why the controlnet hung while trying to merge the changes initially, maybe a version 7 bug with componet revisions?
djs (Electrical)
29 Sep 06 13:32
Hello;
     When rescheduling a Controlnet network, the changes have to be written to all of the keepers. The keepers on a ControlNet network are usually the ControlNet interfaces. However it also appears that the control processors also play a role in this, and because of that, to reschedule a network, all processors connected to that network must be placed into the program mode. A PITA!

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