LM90-30 folder unlock

I'll be working on a 90-30 with a CPU351. End user has emailed me the LM90 program, but the folder is locked to edits (under F8). I remember there was a trick where you could stick the original LM90 3.5" program disk in and then use some magic undocumented key combination (Alt-O?) and override the lock.

Anybody remember the procedure? Can't find it on the web. Or is there another way to edit a locked folder.

Tell the end user to email the password along with the file.

Sorry Steve, it's the typical situation where the SI that wrote the code locked it up for job security. Trouble is, that was awhile ago and he's long gone.

I was working for a distributor when the Series 90 was first introduced back in 1990. At the product rollout sessions the factory reps stressed the importance of documenting the passwords because there is no 'backdoor' way to open a protected folder. I've never heard of the method you hinted at.

The password is a 4-digit hex number. That means there are 65,536 possibilities. OEMs that use passwords need to select one that all their field service people can remember. Have you tried the obvious choices like four digits from a telephone number, a street address or Post Office box, a job or project number (forwards or backwards)? Was the person who wrote the code an employee or a contractor? If the latter, is he still in business?

If I'm not mistaken the Password is held locally.
You can remove the CPU from its shell and clear the memory by jumping the 2 soldier points that read CLR_MEM.
Then reload the program and the password is gone.

The password is included in the file. You can clear the CPU memory and store a program without a password and you'll be able to edit it, but if you store the program from the file with the password to the PLC, you'll find that the password has returned.

Steve,

I put it to the test, I pass-worded access levels 3 and 4, made sure that I couldn't change the logic. Cleared the CPU back to HHP and reloaded the saved file. I was at access level 4 and was able to change the logic. No password.

**The password is included in the file. You can clear the CPU memory and store a program without a password and you'll be able to edit it, but if you store the program from the file with the password to the PLC, you'll find that the password has returned.

**I put it to the test, I pass-worded access levels 3 and 4, made sure that I couldn't change the logic. Cleared the CPU back to HHP and reloaded the saved file. I was at access level 4 and was able to change the logic. No password.

Click to expand...

What a delima, you are both right, how could that be?

OK Russ, since you seem to have taken a page from Peter Nachtwey's stylebook, I'll bite. How can this be???

OK, so I haven't worked on GEF for a year... and my problem wasn't the password (which resides in the PLC and is changed in the configuration package) but that the FOLDER was locked. Offline, in the programming package you can change the folder from locked to unlocked with the TAB key. Very simple, but I just forgot it. Senior moment.

But it got a good discussion going!

Steve, go to GFK0466L, pg 5-5 for info on removing any level of password protection using the Master Disk #1 and ALT-O. This works for 90-30 and 90-70.

I can't replicate what Smoke did (no 90-30) but I remember clearing memory and reloading the program in the past. This is also discussed on 5-5 above.

As always, thanks for the help!

Glad you were able to figure you problem.

I would still like to here Russ's reply.