RS5K Downloading and Tag Values

I've run into this problem the last few times I've downloaded to the controller.

I save project and work offline editing program then download it the next morning and motors start or valves open/close that I don't want to. I beleive this is happening because it is loading the last saved state of values.

Basic Layout
1756-L55M13 with several DNET scanner modules and 1756-ENBT module communicating with 1794-AENT Flex I/O remote rack.

My question:
I want to be able to download to controller and all outputs remain off. I realize that I could go into offline tags and change to a "0" everything that is telling a device to start. I'm looking for global method to turn off all I/O and bit states that may try to open or start a device.

Any Ideas? Also curious if other have this problem and how they deal with it.

Thanks!

Well there are a couple things you can do until a partial download option appears.

#1: RSLogix includes on the CD a utility called the Tag Upload/Download Tool. This would let you specify particular tags that you could upload or download to. Upload the values you want to save to your hard drive then after downloading the program to the controller you can then download your tag values.

#2: Use the First Scan bit (tag is "S:N" without the quotes) in RSLogix to trigger logic to execute on entering run mode. This logic would be programmed by you to execute whenever the controller goes into run.

Maybe someone else can offer something they have come up with.

OG

follow up

Thanks, I've been thinking about modifing logic so that a first scan bit triggers a stop/close to all devices. Due to the amount of ladder to modify, I'm not real excited about it. I was hoping someone had a "global" method. I came up with logic to write all "Real World" I/O OFF but I've got internal logic that will turn outputs back on. Maybe there's a method for turning a internal I/O Off or to a default state.

Thanks Again.

#2: Use the First Scan bit (tag is "S:N" without the quotes)

Click to expand...

Uh, did you mean "S:FS"?

If your plc electrical outputs are wired correctly via an MCR circuit then why not download with the E-stop pushed in (power to plc does not need to be passed through e-stop). The program should be able to wake up and run without any adverse motion.

Bitmore

Sorry, yes...... S:FS

OG

modicon2,

Me thinks you need to re-think some of your ladder logic, if valves are opening or closing when you just download the program, and before you push any start buttons or other controls... Those valves should at least be wired through a Start command that defaults to OFF.

You can do a First-Scan reset of many variables with one command, using the File Fill command, or the File Copy command. You should be able to reset everything in your program to a "default" state with one rung containing 3 or 4 branches (if you organized your logic properly).