1785-ENET losing IP address

Tim Ledwith · Nov 14, 2005

I have a PLC5/40 (1785-L40B) series E revision A, with a 1785-ENET series B revision D Ethernet "sidecar" module fitted. Whenever, I cycle power to the PLC, the I.P. address in the 1785-ENET reverts back to 00:00:00:00.

The PLC5 is fitted with an EEPROM and the chassis backplane switch is set to transfer program at powerup. I have checked the offline copy of the PLC program, and all the channel 3A settings are correct.

Anyone got any ideas ?

Thanks in advance, Tim.

Operaghost · Nov 14, 2005

I don't have a lot of experience with that card but it sounds like the version of the project on your PC may not match the version on the EEPROM.

Sorry if this is too basic, but after you download the project to the PLC-5 did you then transfer it to the EEPROM? I know I will occasionally download to the PLC but forget to transfer to the EEPROM. Then I cycle power and I lose all my changes.

OG

Gerry · Nov 15, 2005

Is the IP address configured as static? Or do you have DHCP/BootP enabled?

Tim Ledwith · Nov 15, 2005

Thanks for taking the time to reply.

OG - I thought this might be the problem too, but I've definitely burned the program with the correct Channel 3A settings onto the EEPROM. I've even tried different EEPROMS and another PLC with later revision (E compared to A) firmware.

Gerry - I have got the "BootP" box unchecked in the Channel 3A setup in RSLogix5.

Thanks, Tim.

Greg Dake · Nov 15, 2005

Well the first thing I noticed was the "00:00:00:00" format of the origional post. That is a MAC address format, which should never change.

I hate that BootP is autoenabled on a lot of devices....

Greg

jstolaruk · Nov 15, 2005

Greg Dake said:
Well the first thing I noticed was the "00:00:00:00" format of the origional post. That is a MAC address format, which should never change.

I hate that BootP is autoenabled on a lot of devices....

Greg

by virtue of the colons only; its missing a few more values to be a complete MAC address.

Contr_Conn · Nov 15, 2005

I would upgrade Processor and ENET firmware first.
Most likely this is a bug related to this particular combination.
If this did not help try to cycle power without Ethernet cable to see if this is coming from the network.

Operaghost · Nov 15, 2005

If you have a BootP utility, see if the ENET card is sending out a request for an IP address when you power it up. I'd be curious to see if that is the case.

OG

Tim Ledwith · Nov 16, 2005

Thanks for the help.

Rockwell Tech Support have advised me to get the firmware updated in both modules, so I'm going down that track.

I tried booting up without the network cable connected, and it didn't make any difference.

I haven't had time to try the BootP utility.

I'll post back when the firmware has been updated.

Thanks again, Tim.

1785-ENET losing IP address

Tim Ledwith

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Operaghost

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Gerry

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Tim Ledwith

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Greg Dake

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jstolaruk

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Contr_Conn

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Operaghost

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Tim Ledwith

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