Mitsubushi Fx program problems

I have recently inhereted a program written by someone else, running program test using GPP developer I found it had over one hundred errors with double coils. Straightening this up will take some time. This Fx processor is using a E900 visual control with quite a few things controlling the machine. I know very little about this visual control, I do have some manuals, but when glancing through them. It confuses me somewhat. For now all I need to know is how to read the signals that are activating my processor program. One example is the control is making a M99 contact hi or lo does anyone have any ideal how I may be able to read this. I'll try hitting the manuals tommorow or whenever I get the time I thought about rewritting entire program which I probably still will. But the original wire / programmer man did not beleive in documentation or wiring vast majority of switches in one state, nor use wire numbers.

Thanks ahead

Does the program in its current form work properly? If so, be very, very careful about modifying that which you don't fully understand. Be sure to make backup copies of the program at key steps of your conversion so that if your changes don't work out, you can return to a program version that was working.

I found it had over one hundred errors with double coils

Click to expand...

Are you sure they aren't SET/RESET pairs, or in different subroutines?

For double coil(or multiple and the same name of output)...you can not use in Ladder diagram ..
(If you make double coil ..It will run at the last rung which has that
coil in the rung.)
Only in SFC(Sequencial fungtion chart)you can make multiple and the same name of output ,but in difference step.
About manual please check from..
www.mrplc.com or http://www.industrial.meuk.co.uk

Best Regards
Platootod

The 'on screen' buttons on the E900 are usually assigned to M relays in the PLC. (either N/O or N/C) Only the bits of these M relays are used, not the coils.
This can make the GPP software declare a problem as it only see's the bits and not a corresponding coil for them.

The double coil error is probably as platood says -there will be some State or Step programming (S Relays) and it is legal to double coil within those as they are only scanned when active.

HMI and Medoc
I have also had the same problem. Many redundant lines from bits removed and loads of alterations which has resulted in double outputs etc. But with a HMI it is so easy to remove bits that look redundant but is in fact still used. The MAC software is the first to look at.
1. File then Melsec in/out naming will import name list from Medoc not sure about GX_Developer.
2. View then in/out cross reference will allow one to see in and outs used. I found D0 in first box with no other entry seems to list both Data reg and M coils.
I have spent ages trying to make up names lists and entering notes but when I import to GX_Developer I lose the notes against the names, also I find it a pain when trying to add notes to find it’s too long so I alter everything in medoc then import to GX_Developer only to test.

I do wonder the std way to select the screen on a HMI? I have used pulse and a cascade of M coils plus Data registers with the 10 options per register. I used a E100 and would love to set up and down keys to change entries rather than type in.

I do agree with others on are you sure they are double coils? Data registers with move and add etc. Can be repeated many times.

Fx2n program

Thanks to all. The particular program I am working on does not have as many double coils as I 1st suspected you were all right on. Some of the double coils appear to within proper programming some are not.
I found out today after using Smartwin software for the E900 the data I am trying to find is D226. After studying program I used a compare statement such as: [cmp D7 D5 m17] this with a added tmr. Made my circuit work very well with one exception, I am using the equal to statement and trying to ignore the greater and less than statements, the only problem must be mechanical or something else because once in a while the equal to statement gets toggled on sometimes, is there some way to block the other two statements using a simple compare statement.

First off, you may want to look at using 'inline comparison' instructions rather than dealing with CMP alone. Then you don't have to keep track of which "M" bits you've assigned to the CMP statement. Someone here clued me into their existence (in the back of the manual) after I was fighting with that old-fashioned CMP statement myself...

I'm not sure I understand what you mean by 'blocking' the other two statements. You say "equal to" gets toggled on sometimes. This should only turn ON only when the result of the comparison is indeed equal. You have to figure out why it's turning on if the comparison is NOT equal. Perhaps you're turning on M18 (your "equal to" flag) elsewhere in the program?...

beerchug

-Eric

Not sure about FX2N as I have only FX0N and FX1N in FX range but the > < and = will not work with these. Only got it to work with A1SJ but the CMP command will not work with A1SJ is that what your talking about Eric? The CMP command is a problem as it uses 3 outputs in one and the auto double coil check will not pick them up. I have myself used the greater than coil in mistake thinking it was free i.e. no star against it in medoc name list. Now I am very carefull to name all three outputs even though all are not used so I will not pick it up in error. As to D226 have you checked little book that comes with PLC to see if its a special? I have been caught out with this before where FX0S and FX0N have diffrent assigned specials. i.e. FX0S D30 is latched but FX0N its not latched until D128 and I have used FX0N program in FX0S and had odd things happen as D30 did not reset.
If there is a way to use < > and = in FX series like one can in A1SJ I would like to hear how. It was very usefull using the 10 number option on HMI so each function was controlled as required by selection of product and setting Data reg from 0 - 9.

The FX1N will allow in-line compares but (I suspect) not with medoc. I think you have to use GX developer.

The A series will not allow the CMP insruction

The sample below is from a FX1N using GX Developer

Thanks I will try that. I didn't think of using all Data reg to do it maybe thats where I got it wrong.