PLC Command

Greetings!

I would like to ask if somebody here knows what is the meaning of a "LR" command at omron plc, am using CQM1 CPU 21 OMRON PLC. All used as NC/ NO contact (not output)

I cannot find on its help file. Thank you very much.

Sincerely,

Sheryl Caño
Philippines

LR isn't a command, it's a type of variable. LR stands for Link Relay.

Kind regards,

Link Relays are pretty old - what PLC do you have?
It probaly has to be 8-10 years old.
Be really careful - if the network goes down the LR doesa not turn off!!!!!

BobB said:

Link Relays are pretty old - what PLC do you have?
It probaly has to be 8-10 years old.
Be really careful - if the network goes down the LR doesa not turn off!!!!!

Click to expand...

The PLC is I quess is a 2nd hand, already used from Japan I think and was transported here (the machine). The model is omron cqm1 cpu21.

What you mean goes down? Trouble occur? If that will happen, what to do next? How to turn it ON / OFF and back to its normal case?

Actually, at auto operation, there is something wrong. There is a sequence that is being by pass. Say after curing time, a timer needs to be energized. Timr then energize. Then, a 2nd timer will ON to cool the product down. However, afer that, it has to be press up and then be release. Now, the operator will get the product. At that instance, it will not press up and release (slide out). Thus, i need now to study the whole sequence and understand where did it stop.

At the program, i saw an LR command in which i am not quite familiar yet. Is this an internal relay? Or, an outside field device? I cannot see it any on the help file available. I hope somebody in here can give some input.

Thank you very much.

Sincerely,

Sheryl Caño

jvdcande said:

LR isn't a command, it's a type of variable. LR stands for Link Relay.

Kind regards,

Click to expand...

Thank you for the meaning. However, I could you could refer me an manual to further explain. Is this an internal relay? Or, from a field device?

sheryl86_ann said:

Thank you for the meaning. However, I could you could refer me an manual to further explain. Is this an internal relay? Or, from a field device?

Click to expand...

LR is an internal PLC data file.
Unless someone else can point you to it, You will have to find the Omron programming manual for that PLC family for a more detailed description.

jimbo3123 said:

LR is an internal PLC data file.
Unless someone else can point you to it, You will have to find the Omron programming manual for that PLC family for a more detailed description.

Click to expand...

Okay okay.. I will try my luck ^_^. Thank you very much.

BobB said:

Link Relays are pretty old - what PLC do you have?
It probaly has to be 8-10 years old.
Be really careful - if the network goes down the LR doesa not turn off!!!!!

Click to expand...

Greetings!

When usually it is being energized if it started at the very first line (whar device needed in order to energize it if it is an internal relay?) No latching? What conditions will it usually turn ON/OFF? Like in other PLC (Mitsubishi), an M is an internal also but it needs an input device first before it can be turn ON like energizing first my push buttons then I can now used my internal relays. I am not so familiar with this "Link Relays" in Omron.

Can you attach here some of your handouts before? Or a website link will do.PLC I am using is OMRON CQM1 CPU 21.

Thank you very much.

Sincerely,

Sheryl Caño
Philippines

The LR Area is used as a common data area to transfer information automatically between two CQM1 PCs. Data links can involve 8, 16 or 32 LR words. LR words that are not used in a data link can be used as work words in programming.

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http://www.datasheetarchive.com/pdf-datasheets/Datasheets-20/DSA-388864.html

Honga said:

http://www.datasheetarchive.com/pdf-datasheets/Datasheets-20/DSA-388864.html

Click to expand...

Greetings Mr. Honga..

I have now your datasheet. I hope this could help me. Are you more on OMRON PLC programming? I hope my doubs can be cleared.I will study it first. Will give an update.
Thank you very much for the inputs.

Sincerely,

Sheryl Caño
Philippines

No sorry, I have zero experience with OMRON systems. Just an avid googler.

hello

LR=link relay same as internal relay (IR),previously i used LR for communicate 2 plc master(cqm1h) and slave(cpm1a)


eliskasim
kluangjohor

The usual reason for using LR is if there are two (or more) Omron PLCs connected together on a network.
The LR data area (words LR00-LR15 or bits LR00.00 - LR15.15) are automatically shared between the PLCs - no instruction required.

For example, PLC #1 may have an input 1.03 described as Stop_button_is _pressed, followed by an output instruction addressing bit LR2.01. (LD 1.03 OUT LR2.01)
In PLC #2 (or 3, or 4...) on the network, using LR2.01 as an INPUT (LD LR2.01) will read the data from PLC #1 as if it were a real input to PLC#2.

I have used LR areas to link and share data between 6 PLCs.

RoTaTech said:

The usual reason for using LR is if there are two (or more) Omron PLCs connected together on a network.
The LR data area (words LR00-LR15 or bits LR00.00 - LR15.15) are automatically shared between the PLCs - no instruction required.

For example, PLC #1 may have an input 1.03 described as Stop_button_is _pressed, followed by an output instruction addressing bit LR2.01. (LD 1.03 OUT LR2.01)
In PLC #2 (or 3, or 4...) on the network, using LR2.01 as an INPUT (LD LR2.01) will read the data from PLC #1 as if it were a real input to PLC#2.

I have used LR areas to link and share data between 6 PLCs.

Click to expand...

Greetings Mr. RoTaTech!

Currently, there is only 1 machine (and also one plc on it). It is from Japan (already too old more than 10 years I think) and they are trying to use the machine. I cannot understand why they are using the LR command and yet only transported 1 unit only.

1. Is it possible that although there's only 1 unit ( or there are 2 or 3), LR can still be used?
2. How could I trace (or know) that it is the 1st, 2nd or the 3rd unit?

3. When I troubleshoot it yesterday, I saw that there is a missing outside wire (an input) x101. Thus, it is the reason why the machine is not operating normally on auto mode (okay on manual mode). Thus, I removed that address in the PLC program. I cannot actually check what's that for. When I tried it, it is operating normally. However, see question # 4. Now, is it possible that that address came from the PLC prior to it?

4. On another selector switch and still at auto mode, I still miss some sequence, sad to say we cannot have its original as built wiring diagram. Is the reason is the LR commands?

Will LR works with or without other PLC? If it will not turn OFF (see above thread), what should I do?

Thank you very much. Hope to hear more.

By the way, are you more on omron plc programming? Mostly here in this circulation are all allen, siemens, etc.. I am more on Mitsubishi.

Sincerely,

Sheryl Caño
Philippines

Here is a link that may help you with how the LR works:
http://forums.mrplc.com/index.php?showtopic=11965&st=0&p=58143&hl=lr*&fromsearch=1&#entry58143
See the pdf shown in post #2. Look at page 3 in the pdf.
There are a lot of Omron posts on that site.
For more help, you might want to post the file you are working on.