Comments Downloading Problem.

Hi

Here is a small problem which I have faced lot many times.
While downloading the PLC program from PC to the PLC unit the
comments in the ladder are lost. If I upload the program from
PLC to PC I only get the ladder steps & not the relevent comments.

In Mitsubishi FX series while downloading the program an option
is given for transferring the comments.But it is always disabled.
I have tried it on S7-224 & Toshiba T1-28 without any success.

A ladder without any comments make life miserable during maintenance
especially if one doesn't have original ladder & has to refer to
the uploaded ladder only.

May be this is done to save memory .
Is there some way to tackle this problem?

Thanking you
asp

Not many plc's let you download the comments with the program to the plc.
Mitsubishi do and I think some omron do as well.

With the mitsubishi FX (and 'A' and 'Q') series, - comments can be downloaded at the cost of memory (or steps)
I do not know which software you are using for the FX but you have to allocate some memory in parameters/memory capacity

Depending on the size of your program, more or less, spare memory can be allocated to comments. (this only applies to FX series with 2k or more memory)

I think all plc manufacturers should do this because I agree with you, it is not easy when all you have is the bare ladder.

It is good when you upload a strange program (strange as in - never seen before) and the comments/labels are there with it.

Thank you Goody.

I will try this memory allocation on FX. I am using MEDOC for
FX series (DOS VERSION).I will go thru the manual for details on pameter settings.

asp

I don't know about transferring comments in MEDOC, but we have done it with GX Developer. You need to allocate A LOT of memory though, as the comments seem to take up as much memory as the program itself. So if your program goes over half of the available memory, you run into problems. Just keep your programs short...

Again, not sure about MEDOC, but in GX Developer if you open up any old version of the program and then read from the PLC, the ladder will be overwritten and be up to date, but the comments will transfer over, so you will at least have the comments for some of the program. Not exactly perfect, but as long as the program hasn't changed too much, it can be a help.

The_Wanderer said:

...the comments seem to take up as much memory as the program... itself

Click to expand...

You got that right! I have only used a few Mitsubishis with this feature, but was never able to store the comments in the PLC because there wasn't enough room...

Nice idea, but only for sparsely documented or small programs... :nodi:

beerchug

-Eric

After 2 weeks of messing around with a Mitsubishi FX-2N 64MR with GPP-win software, the fact that I can load the comments to the plc are all I have found that I really like about them. However as you stated I have noticed it takes alot of room. You would think with Memory prices what they are these companies could make this work for us all.

Just my 2 cents worth.

Bob
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