Thomas Franklin
Member
- Join Date
- Mar 2005
- Posts
- 49
Definately in a bind here.
I have a DeviceNet network, using 1769 SDN and MicroLogix 1500's,
7 Nodes. I need 6 nodes to explicit message to the remaining node. Only 4 of them work, the explicit message fails in the last two nodes to join the network. I can unplug one of the good working nodes and then one of the nodes that was failing begins to work. I plug in the previously working node, and the messaging fails.
I don't think it is my network cable. I have the shield grounded, the V- is tied to to ground. I have a devicenet power supply. My network is only 100 ft. I am communicating at 125Kb. My network ohm's out at 60 ohms. My Can H and Can L are operating within spec. Can H is swinging between 2.5V and 4V, Can L is swinging between 1.5V and 2.5V.
I am looking at the network on my scope, it is definately not a bandwidth issue or noise issue.
I have tried using different nodes. nothing changes. I have completely rebuilt the network new cable different PLC's different 1769 SDN's, different devicenet power supply.
Note: The explicit message only fails if I try and send it to the same node every other node is trying to talk to. If I configure the message to communicate with a different node the message does not fail.
My problem is getting more then 4 nodes to expicit message to one????
This is not cool.....Gonna have to get AB in here, unless someone may shed some light on this situation.
Thomas
I have a DeviceNet network, using 1769 SDN and MicroLogix 1500's,
7 Nodes. I need 6 nodes to explicit message to the remaining node. Only 4 of them work, the explicit message fails in the last two nodes to join the network. I can unplug one of the good working nodes and then one of the nodes that was failing begins to work. I plug in the previously working node, and the messaging fails.
I don't think it is my network cable. I have the shield grounded, the V- is tied to to ground. I have a devicenet power supply. My network is only 100 ft. I am communicating at 125Kb. My network ohm's out at 60 ohms. My Can H and Can L are operating within spec. Can H is swinging between 2.5V and 4V, Can L is swinging between 1.5V and 2.5V.
I am looking at the network on my scope, it is definately not a bandwidth issue or noise issue.
I have tried using different nodes. nothing changes. I have completely rebuilt the network new cable different PLC's different 1769 SDN's, different devicenet power supply.
Note: The explicit message only fails if I try and send it to the same node every other node is trying to talk to. If I configure the message to communicate with a different node the message does not fail.
My problem is getting more then 4 nodes to expicit message to one????
This is not cool.....Gonna have to get AB in here, unless someone may shed some light on this situation.
Thomas