Versa Max not going into RUN mode

Hello Gentlemen,
I have a problem with a GE versamax (NANO)which no one seems to be able to solve, and not being a GE guy(just got the software today),I was hoping someone here had seen it before. The PLC will not go into RUN mode upon power-up. The program is there, and the laptop must be connected to change to Run mode. We tried swapping PLCs to another Versa(this is a NANO). NO luck. I have aske the programmer for any suggestions, but he has been unsucessful. If some one turns the machine off, we have to hook up the laptop. Big Pain. Any Ideas?

I noticed on this unit that there is an input labeled RUN. Could this be the issue? Other NANOs in the plant are similarly configured, but do not exibit the same problem. The fact that we swapped for a new unit and still have the problem tells me that it is a software issue. Could I just wire up the RUN input to a pushbutton, to save time of connecting the laptop? Doesn't solve my problem, but would be better.


Thanks in advance

Update,

Apparently when the power goes off, the PLC loses the program. RUN input won't help for this.

Back to it .

Check the configuration of the CPU for this unit. One of the configurable fields is "Power Up Mode". The choices are "Stop", "Run", and "Last", with "Last" being the default. If someone inadvertently changed this to "Stop", it would explain your symptoms.

The "Run" input is optional. It can be configured as either a run/stop function or as a memory protect function. It defaults to being enabled as run/stop, so you might be able to start the unit by making a momentary connection between the input and DC+.

Thanks Steve. The power up is set for RUN. We have to reload the program if we lose power.

There is no battery on the Nano units, The super cap will maintain RAM for about a half hour. If power is going to be off for longer than that, you need to store the program to flash and configure the unit to read the program from flash on power-up.

Steve,


Thanks Again. How do I verify that the unit is set up to read from flash?
Thanks

The same configuration tab that you looked at to verify that it is set up to RUN at power-up. The parameters are labeled "Logic/Configuration from" and "Registers". The choices are "RAM" and "Flash".

I'm curious about the unit being set up to RUN at power-up. The default for that parameter is "Last", which means that the PLC will power up to do whatever it was doing when power was removed. Most people don't change it. Was someone experimenting on this unit?

History is something I am finding out now.


Thanks Again.

To get the Nano to 'Run' on powerup you will need to either 'Disable' the run/stop switch in the CPUs configuration or wire the 'Run' input.
I believe this is a well hidden feature of the unit.

Russ,

Do you mean that when using the default configuration a Nano PLC will not be able to power up running unless the RUN input is hotwired? It sort of defeats the purpose of having the default power-up configuration be "Last".

If true, that decision makes about as much sense as the decision to make new %Q and %M boolean variables default to retentive in Versa Pro. Thankfully, that was reversed with ME.

Steve Bailey said:

Do you mean that when using the default configuration a Nano PLC will not be able to power up running unless the RUN input is hotwired? It sort of defeats the purpose of having the default power-up configuration be "Last".

Click to expand...

This has been my experience. Yes, it appears that sometimes GE Fanuc allows the Software developers make decisions that should be made by the field engineers.
Because default settings affect all documentation and all users it can be difficult to get them changed.

FYI- On my software, there was no LAST option, only RUN and STOP. The RUN toggle was disabled. The processor seems to be losing the program after power-off, even though we write to the eeprom.

Any ideas?

Oh, you're using Versa Pro software. My VP 2.0 doesn't have "Last" as an option for the Nano models either. I don't know if that got added in later VP versions. Maybe it's only on Machine Edition software.

I've looked through the release notes I have for both the Nano PLCs and Versa Pro software and I haven't found any reference to when that functionality was added to the Nano. You might want to check the firmware version of your Nano unit and if it's earlier than the ones that are working properly, download an upgrade from the GE Fanuc website.

The closest reference to anything resembling your problem was a note about all Nano units performing a checksum test on power-up and if the power-up checksum is different from the power-down checksum, the unit comes up in its out-of-the-box condition. That was in release note GFK-2068E.

Don't overlook the possibility of a defective Nano unit.

Perhaps Russ can get better information. He still works for a distributor and has access to factory bulletins that I, as a lowly Solution Provider and ex distributor employee don't have.

Thanks Steve and Russ. I also now believe it is hardware related, although I was originally told that a replacement unit behaved similarly. It's not a big deal, there are other issues with this machine. I will try the web site again for upgrades tomorrow.

Thanks for the help!

Thread hijack

I am curious now, how do you configure VersaPro (2.02) to use a VersaMax processor?