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QUIPPDUDE (Electrical) (OP)
3 Jul 03 10:53
Which PLC manufacturers and their accompanying software packages offer true on-line editing capabilities.
I have used AB SLC-500 series processors in conjunction with RsLogix for many years and find this feature extremely useful. The program can be modified, the modifications can be tested and finally they can be accepted or rejected - WHILE THE PLC IS RUNNING.
We are considering the AB Micrologix 1500 series PLC's to replace smaller SLC 500 applications - however these DO NOT have the same On-Line editing functionality.

Looking forward to a bunch of replies!!

There are 10 types of people in this world.....
Those who understand binary and those who don't!
xyzz (Electrical)
3 Jul 03 21:05
Yes, unfortunately Micrologix do not have online editing.
IMHO, this disadvantage overweights all the advantages of ML, if any.
From my experience- Mitsubishi online editing is so simple that there is no difference at all between offline and online editing, you just have to be online with PLC.
lesliemcg (Electrical)
7 Jul 03 3:35
another manufacturer is ge fanuc 90-30 series
this offers true on line editing while the plc is in run
i have often changed variables while our machines are in production (even pid motor control)
software i use is versapro (version 2.3) and have no problems
only the hardware config cannot be changed on line, while the plc is in run
JBouchard (Electrical)
7 Jul 03 10:06
Modicon also makes PLC's capable of online editing. They have a variety of different models which I believe all have online editing capabilities. You can find more information on Modicon products at:
madkungfu (Electrical)
12 Jul 03 10:15
ABs new Controllogix line allows multiple users to be online at the same time. We had had three different guys working on their respective sections of the program at the same time. The only thing required is that each user has a local copy of the program open. Worked great. The only problem we have encountered with this is if someone has edits active and another user attempts a full upload.


Artificial intelligence is no match for natural stupidity - Unknown

BC2 (Electrical)
25 Jul 03 15:55
Siemens Step 7 will do a download without stopping the cpu.
hardnose (Electrical)
6 Aug 03 16:09
I am using MODICON's "Compact" series controllers. IMO Modicon's software (LMODSOFT, full-blown MODSOFT (both under MS-DOS)or their newer Windows based Concept software) allow on line program editing. I find Modicon to be the fastest and most convenient programming software if on-line editing is important (it is to me).
One caveat: You better know what you are doing when you make program changes on a running machine or process.
Modicon has also a faster terminal screen update time allowing you see almost instantly what's happening in the logic.
Hope this helps.
xyzz (Electrical)
6 Aug 03 22:31
I think that nowadays the online editing is a rule, not exception in any class PLC.
It would be more interesting and useful to know which ones do not have it.
mrkpmang (Industrial)
17 Aug 03 11:24
AB PLC 5 series allows for a data highway. With the proper hardware/software one can connect almost anything to this network. Sit at your desk and program anything connected in the plant.
OldPfart (Electrical)
25 Aug 03 18:20
Omron offer full online editing on all their PLCs, including the very small ones. The only device they make that cannot be edited online is the ZEN programmable relay.
With the exception of the ZEN, they only have one set of software to cover all PLCs from the smallest to the largest.
tsydrar (Industrial)
20 Oct 03 20:14
I have used PLC2,5, OMRON, MISTUBISHI, SLC100, 500 , But the KING of online editing for me has always been SIEMENS on any of their PLCs and software (excluding of course the EPROM run PLCs which should be antique by now though still working).

JesperMP (Electrical)
21 Oct 03 3:58
I have to comment that I find AB online editing just that little bit better than S7.

AB online editing is really online.
S7 is an offline/online hybrid where the changed blocks are downloaded and accepted by the CPU witout stopping.
How can you "undo" an online editing in S7 ?
OldPfart (Electrical)
21 Oct 03 5:07
Are Siemens still perservering with that nonsense? Glad I do not have to put up with that any more.
Omron's on line editing is so simple both with the older Syswin and with CX-Progarmmer. It is by far the easiest and fastest I have found to use.
With CX-Programmer press Ctrl/E to enter online edit, do your change and press Ctrl/Shift/E anr the change is in the PLC. So simple it is unbelievable.
With the CJ1 and CS1 you can set up to automatically detect baud rate at 115k as well. Really fast.
nutcase (Electrical)
21 Oct 03 6:40
In addition to online editing, Omron PLCs can store address symbols in the PLC memory.  Granted, they need to be downloaded but when you plug into a "strange" PLC the symbol set can be uploaded with the program (assuming the previous programmer downloaded them).  This makes it much easier to upload AND READ a program from a PLC you previously had not connected to.  As far as I know, Omron is the only one that allows this.  It even works in the little micro (brick) style PLC.  This does not require any additional memory card.  You simply section off a portion of the PLC memory to store the symbols.  At this point, rung comments are not stored in the PLC. Oh well.

Vision is the art of seeing things invisible - Johnathan Swift
killemall (Electrical)
21 Oct 03 8:16
The Test and Untest ability of the Allen Bradley PLCs make their online programming facility superior to any other I have used.

Many times I have made big mistakes while online editing and need to undo fast. Any other PLC, and would have been in trouble.

All AB PLCs except the Micrologix range have online programming. That really gets to me, as a lot of my customers like to use the Micrologix range as they are cheap. Comissioning is quite painful.
snafu51 (Electrical)
19 Mar 04 8:03
Triconex offers online editing and emulation capabilities.
ndzied1 (Electrical)
19 Mar 04 10:23
The older SLC 500 line: fixed, 5/01, and 5/02 processors do not have online editing of the programs.  Pretty much in all of them you can go online and change data values and force outputs.

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