DeviceNet

[Conor 4]

Hi guys, I was wondering if anyone can answer a question for me. If we use the Node Commissioning tool when replacing or adding a node to an exsisting DeviceNet network, do we have to download to the scanner card, and put the PLC into program mode? One of our PLC's is very critical and we always try not to have to switch it to program mode unless we really need to. It is a PLC5, but we have most flavours of Ab PLC's here. Conor

[dmargineau 6]

Everytime a PLC5 DeviceNet configuration is modified (even when a firmware revision is revised) you will have to download the Scanlist to the Scanner hence the CPU will have to be switched to Program Mode... DeviceNet is not "spring chicken"... ...It is almost 40 years old... Edited 2 Nov 2011 by dmargineau

[Conor 4]

So I'm as old as DeviceNet, cool Thanks for that

[Ken Roach 194]

Hey, 1995 wasn't *that* long ago. The only A-B DeviceNet scanners that allow you to modify the Scanlist while the scanner is in RUN mode are 1756-DNB with v7 or later firmware. This is the "OSCAR" feature: Online Scanlist Changes At Runtime. Some A-B DeviceNet scanners require only the Scanner module to be put into IDLE mode. Some actually require the controller to be in PROGRAM mode. To my knowledge all the PLC-5 scanners require the PLC-5 itself to be in PROGRAM mode, but it's worth verifying that with RA Technical Support. Commissioning a node for replacement doesn't require any changes to the Scanner if the device is an exact replacement. Adding a node usually means adding to to the scanlist. As described above, this requires the module to be in IDLE mode except for scanners that support OSCAR.

[Conor 4]

So I'm only half as old as DeviceNet then! Thanks for that Ken. I will get on to RA tech support about this. The scanner cards that we have in our PLC 5's are 1771-SDN. We have mainly series B and some series C. Thanks again, Conor

[Conor 4]

Hi guys, I was on to tech support. They have told me that the scanner card in my PLC 5 can be switched to idle when downloading an updated scanlist. The PLC 5 can be left in Run. I am going to try this out tomorrow, so if it doesn't work I'll let you know Conor

[gmferg 1]

PLC 5 requires only the DNet scanner module be placed in Idle mode to make changes to the scanlist. You can replace a device without doing anything as long as the replacement device meets the requirements selected in the "electronic key" setup in the scanlist for this node. I typically disable all electronic keying so that the scanner will allow a device to be replaced by anything else. I rely on the person that is doing the replacement to know whether the replacement is compatible or not.

[Conor 4]

Hi guys, Finally got a chance to do this today. I was able to put the scanner card into idle and was able to change the config fine Conor