AB SLC-500 Beginner Questions

2k1Toaster

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I inherited this aging system and have been asked to migrate it to a new machine. I have no prior experience with the SLC-500 or anything like it, I usually make my own hardware for these sorts of projects.

Right now there are a bunch of valves connected to the main unit and a computer running Windows NT 4.0 talks to the SLC-500 over ethernet.

I am pretty sure I can talk to this thing because I can read and write registers with my new software over ethernet and I can read back the new value I just wrote. However, nothing happens.

Digging deeper it appears this thing is trying to be smart and it actually runs a program? Digging into the NT4.0 machine, I found some files that I have seen mentioned around here, namely an RSS file. I also have an OIS and PPS file if that means anything to anyone.

I also just learned that it needs to be in program mode to accept the new writes, and then run mode to actually do something. However I can't seem to make it do anything. It gladly accepts all my writes with no errors or exceptions and then just sits there mocking me.

Do you have to "program" these everytime power is applied? I thought it had some NVM in it, so as long as the main program is in there, I should never have to write it again. Can it get corrupted? How do I take an RSS file and write it to the SLC-500? Can it be parsed into "write value X into register Y" but thousands of times for the entire file?

What software do I need to be able to read this RSS file? Or can someone parse it for me into something like a text file so I can import it into my program and write it back to the SLC-500?

I am lost because I don't know how this thing is currently working and there is 0 documentation. I had assumed I could just write a register to a value and the valve would turn, but this is much more complex. Any input is appreciated, Thanks.
 
To 'program' the PLC you will need the RSLogix500 Program from Allen Bradley. If you don't have the software already then you must contact your local Allen Bradley distributor.
 
See PDF below for a print out of your program.

You will need RSLogix500 to program your SLC5/05, see link below ( contact your local Allen Bradley repr)

http://www.rockwellautomation.com/rockwellsoftware/design/rslogix500/orderinginfo.html

I have never seen a SLC/PLC without inputs, the program you posted shows only output modules. What software is the NT machine running ( it must be the only source of inputs)?


Eidt: bernie types faster then I do.
 
See PDF below for a print out of your program.

You will need RSLogix500 to program your SLC5/05, see link below ( contact your local Allen Bradley repr)

http://www.rockwellautomation.com/rockwellsoftware/design/rslogix500/orderinginfo.html

I have never seen a SLC/PLC without inputs, the program you posted shows only output modules. What software is the NT machine running ( it must be the only source of inputs)?


Eidt: bernie types faster then I do.

There are no inputs. It literally just turns 6 water valves. It controls the pressure and temperature of each of the 6, and that's it. That's why I thought it would be a simpler interface, it seems way overkill to use this SLC500.

But you only need to program it once right? Not on every power up? This NT system does not have that program on it, and it just boots up and is able to work, no programming or extra things needed.
 
Thankyou for converting that to a PDF so I can see what's in there.

Architecturally, how do these things work? If the unit has NVM, then the program is already in there. How do I say "go"?

I know that in order for any of the other programs to work, the "warmup sequence" needs to be done.

On page 13 of the PDF file, "Warmup Latch" is "B3:0" with the value 13 under it. So do I write "13" to address "B3:0" to "close" that latch? From my previous readings that is a normally open contact, so how do I close it? Do I write a 1 to somewhere, or do I write 13? Once I get the syntax down, I might be able to play with it more. This is a whole new world to me.

Thankyou for the speedy and exceptional replies so far!
 
Aha, So it is the full thing with a bit specified. So "B3:0/13" written to a 1 or 0 connects or disconnects that latch... I see.

So it is a giant hardware state machine then...

Did you use RSLogix500 to generate that PDF?
 
The program should still be in the memory of the unit has been powered, the battery has power or if you have a EPROM module installed.

Just taking a quick look at the program it is a very complicated program. It looks way more complicated than it needs to be. Without knowing how the system is suppose to work it will be hard for us to help.

As for how you "say go" basically you just put the processor in run mode. It should start executing the code. If it is still there.
 
The program should still be in the memory of the unit has been powered, the battery has power or if you have a EPROM module installed.

Ok so there is a NVM option. Looking it up, it appears that if there is EEPROM, it is internal to the SLC500. So is there is a separate part number or identification somewhere physically on the unit (or a register that can be read) to identify itself as an EEPROM version vs. a RAM only version?

Just taking a quick look at the program it is a very complicated program. It looks way more complicated than it needs to be. Without knowing how the system is suppose to work it will be hard for us to help.

Once I figure out the semantics and the basic architecture I can get the program working. It is way more complicated then it needs to be, but if the program is already in the EEPROM, then I don't really care. :D

As for how you "say go" basically you just put the processor in run mode. It should start executing the code. If it is still there.

The more I look at it, the more it appears like a schematic'd version of a state machine. If so, then I should be able to write the registers with the values I know, then close the required latches and off it goes.

It would be nice to have that logic program so I can see the diagrams in a more intuitive way. I am guessing the chopping by page is an artifact of printing.
 
The memory device is a 1747-M13. Look on the processor and you will see a module plugged into it that will have that PN on it

Edit: Can you get online with the processor? Do you have RSLogix500?
 
The memory device is a 1747-M13. Look on the processor and you will see a module plugged into it that will have that PN on it

Edit: Can you get online with the processor? Do you have RSLogix500?

I don't have anything. This thing is 10+ years old and not a single floppy disk or paper printout exists.

I am trying to find software to talk to it, but nothing is still available on the AB site. I was able to find an old copy of MicroLogix but when I open the RSS file it says it is an unsupported processor and never opens the file.
 
Without the activation disk I do t think you will get it to run. If you do it will for only 7 days. If you are going to work with this type of equipment you should just get your company to pony up the money for the software.
 
Without the activation disk I do t think you will get it to run. If you do it will for only 7 days. If you are going to work with this type of equipment you should just get your company to pony up the money for the software.

7 days is all I need if it is in NVM. And if it isn't I will sniff out the packets. I refuse to buy software to make purchased hardware work. If the hardware was free, then I would buy the software. You shouldn't need to purchase both.
 
Ok so there is a NVM option. Looking it up, it appears that if there is EEPROM, it is internal to the SLC500.
Look, that program "BROADMOOR M 4-15-04" most likely is still in the PLC memory (not the EEPROM memory). If so, the LAST thing that you want to do is load from the EEPROM (if it is installed). The EEPROM is an snap-in removable module. The program in it may not be an up-to-date copy, unless someone took the time to copy all changes and modifications to the EEPROM. (The usual case is that the EEPROM program is an early copy without all the changes that were made in order to get the system running). If you load that EEPROM program into the PLC memory, and you do not first copy the internal PLC program so a computer hard drive or USB drive, then you may lose the only working copy. Then someone would have to try to re-engineer all the changes and revisions. BE CAREFUL! Check it out before you do something you might regret.

I refuse to buy software to make purchased hardware work.
Unless your company purchased the Rockwell RSLogix 500 software as an option with the machine purchase, then to get a copy you will have to buy it or do without. That is the hidden "gotcha" that many company managers are not aware when they buy a machine. They assume that they are getting a complete unit with everything necessary to operate and maintain it throughout its lifetime. Imagine their surprise when they find out that it did not come with a spare tire or even a wrench to remove the broken program!

If you found a Version 8.4 copy on a mirror drive, then most likely RSLogix 500 was purchased at some time in the past.

I am pretty sure I can talk to this thing because I can read and write registers with my new software over ethernet and I can read back the new value I just wrote.
This statement implies that there is a HMI program (Human-Machine Interface) running that is trying to send and receive data from the Programmable Logic Controller. If so, that is the operater interface and might explain all those B3 bits used as inputs in the PLC rungs. They could be getting data from the HMI program that controls each valve.

For example, on Rung 0001, the binary bit address B3:0/4 (a single bit in the PLC memory that can only have a value of "0" or "1") and labeled "Head and Body from pm" has no output anywhere in the program that would turn it on or off. B3:0/4 only occurs two places, on Rungs 0001 and 0002. I made a quick search and there are no obvious indirect addressing that includes B3:0/4. That means that it must be turned on or off from outside the PLC. I will bet a dollar that your machine also has some type of HMI, probably a Allen Bradley PanelView operator panel, or similar (maybe even just the RSView operator program). To make any changes, you will also have to understand how the HMI program works with the PLC program (that you posted here).
 
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