blind plc upgrades

[nberna1]

i've be appointed the glorious task of linking with a plc that i did not program.

i have almost no information on the system. i only know that it is a allen bradley micrologix 1500 (which i never have used) and i need (hence recently purchased) rslogix500

so i have to go into this system blind and weed my way through it just to open a pressure relief valve a little bit quicker in one specific situation.

any advice would be well received, even if it is not brand/device specific

thx
nick

 

[xnuke]

Find the I/O point that is wired to your field device. This may take a little bit of work tracing cables/conduit from the device to the controller or wading through drawings, but it'll give you an I/O address - and should therefore lead you in the correct direction toward the code fragment that you need to adjust.

xnuke

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[lrob]

One benefit with the AB PLC is that there should be a local distributor in your area. Each distributor normally staffs an engineer/technician that assists end users with application and software issues. You may want to check on this, it could be a local resource.

 

[djs]

If you can get the orginal electronic copy of the program (it should have file extenstion *.rss) It will probably have the descriptions and rung comments. This WILL make your life easier. Most definitely worth it to get electronic copies for all of your processors.

 

[nberna1]

i had an ab field engineer come check out the system to bypass the password protection. his solution was to erase the memory on the system and install an older version of the software onto the plc (he had a copy of the systems software prior to a huge upgrade). now the system is completely useless... i have to practically reptrogram the sys from scratch