RSLogix 5000 "Lock-Step" - What is this?

[BobB]

Hi Drew
I have used both PLCs and prefer the Omron for fast software development, processor speed, function list etc etc.

You can have the software automatically allocate bits for you but you do not have to. You can allocate all bits yourself in the normal way. This is the way I work. The software, Cx-Programmer, is symbol based. This can be a pain at times but the BIG advantage is that if you wish to change a symbol to a different I/O number, you change it in the symbol editor and it automatically changes all the references in the program. If you go the Omron way, I would suggest you use global symbols not local symbols. European idea and if you do not have it selling PLCs in Europe is becoming harder and harder.

The CS1 is an absolute rocket ship, particularly the high end processors, and has a mind blowing function list. I like that because it saves me writing a lot of code. Omron also have 96 bit input and output cards available for the beast. Saves racks, space and money.

Suggest you have a look at the Omron CJ1. It has the same processors as the CS1 but has no rack, mounts on a din rail, and the modules are about the size of a cigarette packet. Same function list and all. Because of the size, I/O blocks are limited to 64 bits and it would be impossible to increase the density above that level.

They both have huge areas of internal relays and registers as well, dependant on the processor you choose. If you are looking for a platform that has high end and low end processors, the CJ1 is the way to go. High and low end have the same instruction set etc. No need to try to remember waht you have available from processor to processor. The low end CJ1 is also very inexpensive.

Might I suggest you join up and not remain a guest.

beerchug

 

[Drew]

Thanks BobB! What else do you know about Omron?

Thanks Bob -- I saw the CJ1 PLC today! I am glad you suggested I do this b/c it is much smaller, uses the same software, and EVEN the same cable as the other Omron PLCs. We will probably specify this instead of CLogix or CS1 unless there is a reason someone knows that I should not...

In your experience, can you think of any negatives about the CJ1? (I don't need the 98pt card). I still can't believe you can get a 64pt card in that size even though I probably won't use it either.

The engineer who came over to show the CJ to me showed it supports full networks (Ethernet, DeviceNet, etc.) He said it is pretty much the CS1 but smaller and no backplane like you said. Major difference he said was motion control and Profibus not supported (only position control -- this should be OK for us). Same instructions, software, etc.

After reading the posts here and checking out facts, I really like the way Omron is going in the future. It looks like they are making it easy for older users to upgrade while still giving some advanced new features to keep up with the times.

BobB -- I have a couple more questions for you:
1) Could you describe a little more about the symbols and if Omron is different from CLogix "tag based"?

2) What do you know about Omron new NS touch screens? I heard you can pull up PLC code right on touch screen for troubleshooting but I did not see this. Do you know about this new product?

3) How does Omron's DeviceNet I/O match up to AB? (Diagnostics, maintenance features, etc.)

Thank you for your help!
PS -- I registered today!!!

 

[BobB]

Very good is it not Drew. Yes - has all the networks except Profibus but I do not consider that a downside as I am not fond of Profibus. Controller Link is brilliant, fast and seamless. Much better than Ethernet for PLC to PLC communications.
1) Symbol and tag based are much the same thing. Eg:- RP1STT (Recirculating Pump 1 Start) is a symbol and, I believe a tag in AB. The address is a different thing and in this case may be 000.13 (input channel 1 bit 13). I also like no X, Y, I, Q, %I etc. For that address enter 1.13 and CX does the rest for you. CX automatically labels inputs and outputs I and Q for you and in the "tools" section you can change these to X and Y. CX is very configurable for short cut keys also. Makes life very easy instead of getting RSI dragging and dropping with a mouse.
2) Not familar with the new screens but I believe they have a computer on board so it would not surprise me if this could be done.
3) Handles Device Net very well. I have used the older C200H Device Net Scanners on the CS1 with 6 Device Net scanners on one PLC. These were coupled with 80 odd Omron Device Net I/O blocks in various switchboards to monitor status back into a Citect SCADA system. The PLC is also controlling various ATS units. One scanner is dedictated to a network of Allen Bradley Powermonitor 3000s. They are addressed by explicit messaging to extract current, kWatts, var, voltage, frequency etc. Explicit messaging is a pain at first but works well when you get it going. The only problem is the way the information comes back. You have to use the "swap byte" function and then the "transfer" function to get the words in the right order. That is the only problem with data coming back that I have observed. Part of the problem with getting the system going was the original Configurator software. As with most first releases it was a bit basic. The latest version is very good and with the Cs and CJ PLCs you program the scanner from the programming port on the PLC. Very quick and simple.
At the moment I have a job in progress to upgrade and fix the maintenance cranes on the Sydney Harbour Bridge. I am using Pepperl + Fuchs Device Net absolute rotary encoders. The process is slow so network response is not an issue. If it was, these devices would be no good. Would have to use high speed counter cards. The great thing is I can change the resolution per rev and total resolution straight from the Device Net Configurator to suit my application. The encoders support all forms of Device Net communications and all I had to do was allocate 2 channels for the reading of a double word from each encoder.
The only trouble shooting tools I have found that are Omron specific are incorporated in the Configurator but have not really had any problems. I know there are 3rd party troubleshooting tools available. Check on www.odva.org. Lots of good info, links etc for Device Net products. They have also taken control of Ethernet IP.
beerchug

 

[BobB]

Can not really think of any negatives for the CJ1 with the exception of lack of Profibus support, if you like Profibus.
The only other thing Omron have done is they do not supply the plugs for the high density units. Probably makes sense as most people buy made up interface cables. I don't. I make my own to varying lengths so that I do not have any terminal blocks wasting space in the cubicle. Run the wires straight up to the push buttons and lights on the doors.
I have checked out the NS and yes, you can show ladder on the screen, if you buy the software to run it. Fairly useless to me as a developer as it is read only but may be of some use to all you maintenance warriors if you can page through the ladder looking for inputs that do not come on or something like that.
Cheers and enjoy.
Definately worth a couple of beers.
beerchug
beerchug

 

[Mike]

Bobb & Drew,

I have used the new NS screens as well as the ladder monitor software in them. You can view the PLC program right on the HMI without hooking up any computer or cabling. Bob, you are not quite correct in your statement that you can only monitor the program, you can in fact make some changes, but it is limited. The cost for the software can be added to the NS is less than $100 per unit, so it is worth every penny.

I would like to point out however that all of the Omron touch screens, NT & NS has a handheld programmer screen which you can pull up and make as many programming changes as you like, and this is a standard feature.

One thing that you forgot to point out is that you can store up to 20meg of data on the NS, this has allowed me to store drawings, trouble shooting manuals, and pictures of the machines directly on the NS, and they can be viewed without any PC being needed. This is a really cool feature for the maintenance guy's.

As for the biggest difference between the CJ1 and the CS1, which may effect you it sounds like is the amount of I/O which can be used with each unit, 2,560 local I/O for the CJ1 and 5,120 for the CS1.

As for the CL vs. the CS1/CJ1 there is no comparison, the Omron products will beat the CL hands down in speed and in easy of use. I have a customer who installed a CL system and after a few months had an I/O module which went bad. They installed a new module, which was purchased along with the original hardware and shut the whole network down because the firmware in the replacement module did not match the existing hardware; it had a newer firmware revision in it. They had to flash each module, back plane, power supply and processor on their system so that everything had the same firmware revision on it. When they did this and then attempted to reload their program it would not load because they had run out of memory! Each of the firmware flashes takes up memory, the AB web site even tells you that you must look at the size of the firmware upgrades and your program size before you flash the hardware, something I don't think they like to talk about.

The customer also found out that you couldn’t go back and remove the upgrade so they were told that they would have to buy new processors. If you go to the AB web site you will also find that they have had over 240 revisions to the CL platform since it's release about 4 years ago, so the statement that they only have a few major revisions every year may be true, but what about all of the minor revisions. Just something to think about........

Mike

 

[Ken Roach]

Mike, you can cheer about the Omron features all day long, but wouldd you mind laying off the exaggerations about ControlLogix? Your last two paragraphs may be "based upon a true story" but contain about 10% fact.

Flash firmware upgrades do not "each take up memory" and there have not been "240 revisions to ControlLogix".... adding up the number of available modules and multiplying by the number of releases is a clumsy way to extrapolate.

"they had to flash each... power supply... ".

Puh-leeze !

 

[Peter Nachtwey]

When they did this and then attempted to reload their program it would not load because they had run out of memory!

I don't believe this. The new program writes over the old program in flash memory.

Each of the firmware flashes takes up memory, the AB web site even tells you that you must look at the size of the firmware upgrades and your program size before you flash the hardware, something I don't think they like to talk about.

Post the link. Yes, each flash takes up memory, but not more memory than the space alloted to it at design time. See the above.

The customer also found out that you couldn’t go back and remove the upgrade so they were told that they would have to buy new processors.

We have had to go back once or twice. We did it.

If you go to the AB web site you will also find that they have had over 240 revisions to the CL platform since it's release about 4 years ago, so the statement that they only have a few major revisions every year may be true, but what about all of the minor revisions. Just something to think about........

Most of those are never released or or not really changes. The motion modules all have the revision number increment even if there is only a small change in one of them. This makes it easier for the users to be sure that all their motion modules will work together.
Where is the link to 240 Control Logix revisions?

 

[Mike]

Peter,

You are correct in stating that "The new program writes over the old program in flash memory." However if the new revision is larger than the old version it does take up more memory.

Peter you asked me the following:

Post the link. Yes, each flash takes up memory, but not more memory than the space alloted to it at design time.

I will do one better here is the section out of the Word document off of the AB web site pertaining to revision changes. As you can see it plainly states that you must check your memory that you may have to add a memory card or replace the existing memory card with a larger one, because the revision takes up more memory.

As for all of the other links here it is with all of the information:
http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/$$Search?OpenForm&Seq=1




Controller Memory Changes

This revision of Logix5000 controllers requires more memory than previous revisions:

· Before upgrading to this revision, check the amount of unused memory that you have in the controller. To upgrade to this revision you may have to add an expansion memory card to the controller or use a larger memory card. To check for memory usage refer to the Knowledgebase document A2838854 at http://support.automationrockwell.com
· To estimate the additional memory that your project will require, use the following table.
· For additional information about controller memory issues refer to the Knowledgebase document G19984 at http://support.automationrockwell.com Additional memory to upgrade to firmware revision 10.x

 

[Ken Roach]

There's a saying on some of the nontechnical bulletin boards I participate in: "DNFTT".

 

[BobB]

H Drew
Something else that may interest you. There have been various discussions on many sites about problems with USB/serial coverters. Many of us have been caught with these B***** things not working properly, causing communications drop outs etc. Some work better than others and then you get an updated set of programming software and the damn thing stops working again.
In frustration you contact BB Electronics, or someone else, and buy a PCMCIA serial port with all lines wired out so your PLC communications are happy again.
Interesting point is that people like NEC are supplying laptops with proper 9 pin serial ports again. Bought one the other day and gave an almighty cheer. Worked first time.
I am lead to believe that Omron have taken the bit between the teeth and have updated SC1 and CJ1 processors on the way USB programming ports. Brave move but it if works it will be brilliant. If it doesn't, we will all curse them for ever and a day.
:nodi:

 

[ripro]

Do-Not-Feed-The-Tigers???

 

[Eric Nelson]

Do-Not-Feed-The-Tigers???

Close... Replace "Tigers" with "Trolls"...

Or, if we wnat to stay "on-topic", it could also be the "Timer Timing" bit of a timer with the nickname DNF...

DNF.TT

beerchug

-Eric

 

[Drew]

Omron USB Port

BobB - I asked this morning about Omron USB port, and I think you are correct. It looks like USB is coming to CS and CJ processors. I also heard it is coming to the HMI. This should be a good addition.

It seems this post has taken on a life of its own with some other conversations....

Anyway - thanks for all your help BobB!