Converting MELSEC IL to LD on A2SH(S1)

[mitsibushiman 0]

I have been asked to look at a PLC program in a A2SH(S1) PLC, Normally i use GX IEC Developer v4.00 for this kind of work, the problem i have is that whenever i try to upload the program from the cpu to my laptop with gx iec dev in symbolic mode i get an error message saying symbolic information not availible do you wish to upload in MELSEC IL. I can upload from the cpu in MELSEC IL no problem, but as you can imagine fault finding on a machine in IL is a no goer , I really need to get this program in LD format for accurate fault diagnosis, does anyone know of any way of doing this or converting the IL to LD in gx iec dev. Could this be because the program was originally loaded in IL format?????? and is there any solution?? Any help or advice gratefully received PS I had nothing to do with this program when it was installed on the machine in question (rival contractors!!!! <> )

[navillusi 2]

Sounds to me like the program was not written using IEC developer. If it were, the symbolic information should translate the IL into whatever language it was programmed in, i.e. ladder, FB, ST etc. If IEC developer reads a program from a plc which contains no symbolic information you will only ever get instruction list, and no, there is no way to convert it. This is also the case when the original program was written in IEC and then someone makes a modification to it using another programming package, what happens then? You loose the symbolic! I would suggest using the propriatory ladder programming package to read the program - GX Developer or even DOS Medoc, this will translate the IL in the memory of the PLC to ladder format. One tip, if you cannot see a FEND instruction in you instruction list, then the program was never written in IEC!! As IEC developer will always insert a FEND instruction before the END whether it needs it or not.

[mitsibushiman 0]

Cheers, have a sneaky feeling its been written using different software i have an old version of DOS-MEDOC kicking about somewhere ill try and load it into that, (groan-itll be like going back to step5-the first software i ever used!) Thanks for the reply 10 Minute later update - there is a FEND instruction in the LD, so the prog has been written by gx iec dev, hmmmm strange so why cant i download the ladder, cos its been uploaded in IL???? Edited 1 Jul 2003 by mitsibushiman

[Crossbow 294]

The presence of the FEND doesn't neccessarily mean it was written in IEC Developer, but if it was, that instruction is always present. I have seen those in GX-Developer and MEDOC programs before. I've never used IEC Developer, just GX-Developer 7 and 8. But in GX-Developer, you can upload the IL and it will show it as a ladder diagram. Sorry can't help with the IEC Developer though.

[mitsibushiman 0]

Managed to get a copy of GX Developer and sort it out from there, machine running perfect now! Thanks for all the help !