Mitsubishi Melsec-A PLC

Hello everyone,

I have a Mitsubishi MELSEC-A PLC with A2USHCPU that I'm having a problem communicating with.

I have MELSEC MEDOC VERSION 2.30 programming software.

When I first started working on the PLC I was able to communicate with it using a Windows 98 PC, but when I tried to upload the program from the PLC it gave me a memory error. That error stated that there was not enough memory. I don't know what that means. Now I can't communicate with it at all. I don't remember changing any settings so I don't know how I lost communication.

I have tried with a Windows 98 PC and a Windows XP PC. I could never get the XP machine to talk with the PLC.

I would greatly appreciate any help.

Thank you,

noorgul

If you could communicate - and now you cant, it is not very likely to be the PLC.
Somewhere on your PC, your communication settings have changed.

The first thing to check is are you using COM 1 - something else might be using it and MEDOC wants to use it but cant.

There is nothing else running on the PC. The COM1 settings are the same for the PC and the PLC.

what kind of cable is connecting them?

SC-09 by Beijer Electronics.

Mitsubishi A serie PLC are somewhat funny.

I have in the past had tu use different models to establish com.

After talking to Mitsu's rep, I was told that its sometimes like this when there is a different firmware inside.

Different from what? Who could tell if the manufacturer couldn't?

So, a shot in the dark: Try different A serie model number.

I was able to connect to the PLC. The issue I'm having now is that when I try to upload the program from the PLC to the PC I get the following error: 'not enough memory, program truncated.'

noorgul
You may need to add an "e" switch when you launch Medoc. There are a number of options available for this but you will probably just need to use "Medoc e". As you seem to be able to connect to the PLC already you should not need any other switches but it can be difficult finding a setup which will work with XP.
Andybr

yes,medoc generally does those funny tricks ..anyway.

1. Uninstall your medoc and then load it again. Save your code first.

2. Check the memory allocated to the program, you can write a small code and see if it can be loaded if yes ..then "verify" also ..this way you can corner the fault ..

There is no installation involved. I just run the Medoc.exe to get the program to run. How do you check how much memory is allocated for this program?

yes of course you have a software ..that needs to be installed to run the whole thing...and after that only you get that .exe file ..so delete the whole software and reload again..

There is no setup program. How do I reload?