Can I replace a PLC5/40 with a PLC5/20

[mapizarro]

We have a line with 28 belts conveyors controlled by a plc5/40.
In our stock room we only have a plc 5/20.
Is there a way to check if the 426 rungs program will fit and run with a plc5/20.

The plc4/40 have two full racks.
thank you for any help you can provide me.

 

[rsdoran]

I "THINK" the only issue in this case would be memory, check the file and see how much memory was used and if the 5/20 has enough. A simple method would be attempting to load the program. 400 rungs isn't that much.

I would keep the original "as is" and import it into a new file with the 5/20 configured the same before attempting the load to plc.

 

[allscott]

Shouldn't be a problem, do as Ron said and simply change the processor in Logix and see what it says, it is going to ask you if you want to resize the data tables.

There is a difference between a 5/40 and a 5/40E. If you try to change a 5/40E with a 5/20 you might run into issues, The enhanced processors offer instructions that the standard controllers do not.

But generally speaking the only difference between a 20 and a 40 is the amount of memory.

 

[Ken Moore]

The "enhanced" plc's support file types such as pid files, msg files that are not supported in the 5/20. If you use these files, you will have to modifiy the code to use "N" files instead.


As others have said, open the project in Rslogix 5, change the processor to a 20 and compile the project, if there are any "gotcha's" they should show up as errors.

 

[Gerry]

Come on, guys.
The difference between 5/40 and 5/40E is ethernet.
A 5/20 is an enhanced PLC5.
For the record:

• 5/10; 5/12; 5/15; 5/25 are "classic" or 1st generation PLC5's
• 5/11; 5/20; 5/30; 5/40; 5/60; 5/80 are "new platform" or "enhanced" PLC5's

The only differences between a 5/20 and a 5/40 are memory size, I/O capacity, and number of comm channels. The instruction set is identical.

Selected models of the "enhanced" PLC5's have different suffixes to their model numbers:

• L - extended local I/O (as opposed to Remote I/O)
• E - Ethernet
• C - ControlNet

 

[m.nazish]

Is there any connection between Ethernet/IP and PLC-5/30A or PLC-5/30C? I mean if we use PLC-5/30A or PLC-5/30C for communication with Ethernet/IP, will that work?

 

[(8{)} ( .)]

But generally speaking the only difference between a 20 and a 40 is the amount of memory.

...and the number of I/O racks the controller supports.
...and the number of blue hose ports (5/20 has 2 ports, 5/40
has 4)

BTW, if the program doesn't fit you should try to delete unused
memory-eaters such as MG and PD data types. Also insure that
you have as few as possible unused files. For example if you
have program files 1-20 and no other files until file 50 you
should move file 50 to file 21 and delete file 50 (don't forget
to change any JSRs or SFCs that reference file 50.

The same thing goes for data files.

Good Luck,

(8{)} .)

(Yosi)

 

[jdbrandt]

Couldn't you also just pull up the existing program, change the project to be based on a different processor, and try to save and verify it on a laptop? Same result, I would think.

I do this now...I'm writing a ML1400 program, using a 5/03 that I have for logic testing. Every day (or so), I create a dummy project, and try to save and verify, just to make sure the instruction set is consistent.