Trying unsuccessfully to download a new program into a PLC5/30

[Jimmie_Ohio]

Just got home from dinner & a few drinks. I'm on it boys (& girls).

Best way to troubleshoot PLC's (or anything for that matter).

 

[Ron Beaufort]

Also the new program was configured as node 21 and my PLC is configured as node 1.....my PC is node 0.

this isn’t part of your problem - but you might need to know it for future reference ... your processor has two basic communications links ... (for simplicity, I’m ignoring the Remote I/O link for now) ...



Channel 1A is the DH+ port (Data Highway Plus) ... the node address (00 through 77 octal) for this port is set by using DIP switches on the back of the processor ...



Channel 0 is the DF1-RS232 port ... this is the one that you’re currently using to communicate with your processor for programming purposes ... this particular port is technically called a “Point-to-Point” connection ... basically that means that you cannot “network” this connection ... specifically, you can have one device (your computer) located at one end of the cable ... this will be “Node 0” ... you can have another device (the PLC) located at the other end of the cable ... this will be “Node 1” ... big source of confusion: the “Channel 0” port on the front of the PLC-5 is “Node 1” as far as the “DF1-Point-to-Point” setup is concerned ... and the DIP switch settings on the processor won’t affect the node address on this particular link ...



so that’s the basics ... but ... most (ALL?) of these “rules” can be changed by various configuration settings ... but this is a good place to start ...

... can anyone tell me how to change a processors name once it is online?

glad to see that you’re making headway ...

 

[ptine]

Thanks guys.

 

[ptine]

I'm experimenting with files names at the moment. I'm trying to find out why (at work) when I go online to some processors I get the prompt:

"Going to online programming state" and then I have to choose the "Upload logic, Merge with existing comment/symbol DB". When this happens at work I usually see several files at the bottom of the prompt under "files found with matching online processor name/password. I choose the appropriate one and away we go. There are 9 guys at work who access the system so it is hard to keep track of what they are doing. I'm not experiencing this at home and have been unsuccessful in replicating it.

What I'm doing with my newly downloaded program is I'm going to the location that it is saved in my computer (RSLogixs Projects) and using the windows rename function to rename it. If I put the .rsp extension on the file when I go online with the processor it finds this renamed program and meshes it with the program that is loaded in the processor automatically without prompting me for any other information.

However, just as a learning excercise I have tried to rename it without the .rsp extension and of course the processor doesn't find it when I try to go online. I have tried to use the browse option when I'm in the "going to online programming state" and I get a very small window that pops up titled "look for plc source file" with a list of all the folders I have on my c drive that have .rsp files. I highlight "RSLogixs Projects" and click OK and it doesn't find the BAK files of the original program that I have renamed without a .rsp extension. This window will not allow me to open the "RSLogix Projects" folder and manually choose a program. My only option is to highlight the "RSLogix project" folder and click OK.

If I choose "create new file" from the "going to online programming state" window I upload only the barebones (no symbols/descriptions) logix program that is stored in the processor. I was hoping that RSLogix would scan the folders that it listed when I clicked on the browse command and check for any files that matched the program that is stored on the EEPROM in the PLC. Am I missing something here, is there something that I can configure so that RSLogix will react differently?

I guess what I am asking is why am I always getting prompted (at work) to "upload logic and merge" with several versions of the program being listed under the "files found with matching online processor name/password". What is causing this to happen? How do I stop it from happening?

Also what parameters does RSLogix use when searching for an offline program to match the program being stored in the processor? How come it doesn't find the BAK version of the program that is stored in RSLogix Projects and prompt me to use this program.

I apologize for being all over the place but I'm short on time. Thanks.

 

[Freak]

RSLogix always looks for the last saved version, ie the PLC remebers what it was called the last time. Where I work we also have a lot of problems tracking the latest version of programs, in one section we always reserve N7:255 for a version number and then increment it by one, this number is then saved with the program name and displayed on the touchscreens (where there are ones) so at least you know if you have the latest version or if not how many revisions you are out.


Does anyone have a good method for tracking preogram revisons where the are multiple internal and external users?

Cheers

 

[ptine]

Can anyone please direct me to a thread or post an explanation on what the best way is to capture those screen shots so that we can post them in our questions? THANKS.

 

[Mickey]

I use this:

http://www.mirekw.com/winfreeware/mwsnap.html

 

[ptine]

I guess what I am asking is why am I always getting prompted (at work) to "upload logic and merge" with several versions of the program being listed under the "files found with matching online processor name/password". What is causing this to happen? How do I stop it from happening?

Thanks.[/QUOTE]

Anyone have the time to elaborate on this one

 

[Ken Moore]

On the newer enhanced plc-5's the processor generates a checksum everytime the program is saved. So if Bill goes on line and saves the file a checksum with the value of x is saved with the file. Then Bob comes along and goes on line the saved file on his pc has a checksum with the value y. Since y does not equal x, you have to preform an upload to ensure you have the latest logic, that's actually running in the plc. Now in my previous example, if Bill went back on line before Bob did, the checksums would match and no upload would be required.

Make sense, clear as mud?

On the "classic" platforms, you don't have a choice, you always have to an upload. I believe this is because they lack the checksum feature.
So if you have a 5/10, 5/15 or 5/25's at work you must always do the upload.

 

[ptine]

I just checked my 5 out and found the current checksum in the controller properties in the project tree. I just did some quick conversions and couldn't correlate any of the values that I found.
Program files 12 words 2633
Data files 61 words 3263
Overhead 438
Memory used 6334 words
Free memory 26434 words
Program checksum e2e8

I thought that perhaps if I converted e2e8 to decimal 58088 and tried to reverse engineer it I could come up with the algorithm. It sounded really solid in my mind but I can't get it to compute. Strictly curious, does anyone know how this all ties together.

 

[Ken Moore]

Just guessing, I would think the clock/time might be part of the checksum. The same plc, without any changes, will generate a different checksum everytime the program is saved.
But...why would you want to reverse engineer it? The checksum ensures that what you go online with, is what's running.

 

[ptine]

just curious how it all gets tied in together. Every little bit of knowledge helps at my stage!

 

[rPraveenkum]

In plc5 checksum will be calculated by the processor offline file will do that