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distance from expansion modules


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Hi Perry,

With expansion adapter EX-A2X or with XL expansion modules/adapters EX-DI16A3-TO16 and EX-DI16A3-RO8 (not with EX-A1!) the max length between the congtroller and the expansion module is up to 20 meters (65.6 Ft). Additional less than 4.5 feet are not critical.

Very important: The expansion cable must be produced in Unitronics factory to follow the strict technology. This will provide requested stability in communication. Please contact your local Unitronics representative for more info and order.

In addition - you need to avoid passing the cable along with high power and high frequency cables.

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I have a vision 1040 and I want to locate my expansioin modules 75 feet away

using a good belden/twisted pair/shielded cable. I have been told that distance

will be pushing the limit.

Perry

Food for thought,

You could get another small Uni with CAN and go UniCan between that and the V1040. then use a short expansion cable to you remote I/O, or, if there is enough, jsut use the I/O on the Uni.

In this way you could use the Uni as a passthtough with the fringe benefit of having a remote HMI.

D

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Good suggestion, Damian. Or you could use an EX-RC1 and make the I/O a remote drop. The V1040 has a CANbus port. Either way, it will make a more stable installation.

Getting a super-long expansion cable made by the factory is going take a few weeks.

Joe T.

Hi Joe,

I agree. If you need a lot of IO at that location, the EX-RC1 makes good sense. If you only need a handful of IO it can sometimes be more cost effective going with the likes of a V120-22-RC6, which is cheaper than getting a EX-RC1 and an IO-DI8-R08 for practically the same IO. Then you get a Bonus screen to boot for displaying status or maybe as a remote HMI as well as bonus comm ports. The fact that the EX_RC1 isn't battery backed might also sway that decision.

Not certain why Emil is adamant about using a Unitronics made expansion cable. At the end of the day it is just shielded CAT5e. If you purchase good quality shielded connectors and know how to make an Ethernet cable this is about as easy as it gets. You just have to make sure and maintain the correct twisted pair relationship and extend the shield wire out for termination at one end. I always make my own expansion cables just so that I can make them exact length. I have never had an issue with a hoe grown cable.

D

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There is an interest point here: why the EX-RC1 + IO is more expensive than a V120?? It's the same with the IO remote modules of others manufactures (WAGO, BECKHOFF, CREVIS, ETC, ETC)

I have used Jazz instead of this kind of modules because the prices.

When the number of I/O is bigger the story is different of course.

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Hi Damian,

The quality of the cable between the controller and EX-A2X or XL modules-adapters is very important for the stable, drop-free connection. It's quite not so simple as you says.

Please - if you don't want to follow the right instructions and take the full responsability for any further problems you will have - it's up to you. But - please - don't teach the other to make wrong things! Then they can understand you wrong, have problems and will come with the problems to me, not to you! And I really don't want anyone to have problems with Unitronics stuff - never mind who is guilty. So - please again - let's follow the rules!

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Hi Damian,

The quality of the cable between the controller and EX-A2X or XL modules-adapters is very important for the stable, drop-free connection. It's quite not so simple as you says.

Please - if you don't want to follow the right instructions and take the full responsability for any further problems you will have - it's up to you. But - please - don't teach the other to make wrong things! Then they can understand you wrong, have problems and will come with the problems to me, not to you! And I really don't want anyone to have problems with Unitronics stuff - never mind who is guilty. So - please again - let's follow the rules!

Hi Emil,

I sympathize with you when it comes to people coming to you with their problems. I started out in tech support, and as an integrator that role never really vanishes. The vast majority of the time it was quite simply the customer's fault and rarely a legitimate issue with the equipment. Either they didn't read the documentation, didn't follow instructions, or simply were not qualified to be doing what they were doing.

However ...... if everything went perfect and nobody ever did anything wrong......... If customers didn't need help, then your job, as it exists right now, would not exist. It is a common for me to hear maintenance personnel from various companies I visit complain when a machine breaks. It makes me wonder why they think they were hired in the first place.

I do take exception to the assertion that what I have said, and the cables that I have made for myself are "wrong" or are somehow lacking in quality. On what basis do you make this claim? You haven't had to field any calls from me on this, and you haven't seen what I have made. If you would like, substitute the word "right" with "recommended". I have not used the newer EX-A2X expansion module yet. Perhaps the cable for that is "fancier" than the simple shielded cat5e cable that came with EX-A1. I don't know, so I can't speak to it.

To a larger degree, I think it is worth asking the question of "why are we making a simple expansion IO module that requires a fancy cable to work properly in the first place". I look at all the other technology we utilize (Profibus, Ethernet, CAN, etc.) Why wasn't the expansion comms done with something more inherently robust? I use other bus systems that are just as fast as the expansion comms that utilize simple un-shielded twisted pair wire. I think there is something fundamentally wrong with the idea of designing something involving communication to a remotely mounted device that doesn't allow you to "cut to length" the cable that you need. From a practical standpoint, when we are first designing systems and ordering material, we rarely know beforehand exactly how long cables will need to be. So by your recommendation, I always have to choose between possibly ordering a cable that is too short, or possibly one that is too long so that I have to find a place to "hide" the excess loop of cable. Or as a third option, I can wait until after the system is built, and then put everything on hold for a few weeks while Unitronics is making my custom length cable.

I have also not instructed or taught others to do anything wrong. Everyone else can make their own decisions on what their capabilities are and what they feel comfortable doing. For this application, I would not recommend an expansion cable of any kind, no matter who made it. They are better off using CAN at that distance. The key to minimizing calls to support and trouble with the product is to provide the customer with the tools necessary to do things properly. Rather than insisting on making everyone’s cables for them, it would be far better to post a drawing in your documentation library that instructs people on how to do it themselves properly.

D

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Hi Damian,

First of all - thank you for taking time and answer to me so detailed!

I want to appologize, if my previous mail was a little "spacy". Even we don't know each other personally, I think about you as a colleague and friend and I think frends can speak more direct. Excuse me if I was wrong!

About the points mentioned in your post:

The description of cable for EX-A1 is posted on the spec of EX-A1. This means, that everyone can follow this instructions and make his own cable. This is not a matter of discussion and not something I had in mind. It seems there was a point of misunderstanding.

According to our R&D, the quality of the cable for EX-A2X and XL modules-adapters is very important for the stablilty of the communication. I have detailed doc with instructions about such cable, but the decision is not to publish it. I'm sure, that if you have this spec, you will follow strictly its instruction and your cable maybe will be even better than the one produced serially in our facility. Probably another 40, maybe even 60% of our customers will do the same. But what about the others?

I understand very well the problems the decision not to publish the spec of the new cable causes in the field. Do you have idea how to break this circle?

To a larger degree, I think it is worth asking the question of "why are we making a simple expansion IO module that requires a fancy cable to work properly in the first place".

Very good question. But please note - this communication was made about 10 years ago. In these times this was the best soluiton as ratio price/performance. Changing it now will make existing systems incomatible with the new ones. Maybe in some moment we will really do it. You understand - this is not an easy decision.

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Hi Emil,

You have nothing to appologize for. I like the fact that your direct and blunt and not afraid to speak your mind. I enjoy this forum, and you have played a key role in making it what it is. I think of it almost as a "Hitchhikers Guide to the Unitronics". I very rarely run into a problem that I have to ask for help with, and this is because more often than not the answers lie somewhere here in this or the old forum. You are an asset to the company. Please don't ever feel you need to choose your word's carefully with me.

I tend to forget that the EX-A2X exists. Looking back at what you wrote, it was very clear you were talking about this, so the mis-understanding was all on my end. So for that I offer you my appology.

I understand the position Unitronics has taken regarding not publishing the specs on the cable. I don't agree with it but I do understand. Based on my experience, people are going to do it anyway. So you are better to give them the info and better their chances of getting it right as opposed to "winging it". You will never be able to stop customers from doing "dumb" things. Your only recourse I think is to keep things as simple and make things as robust as possible while still fitting into the economic framework your targetting.

Keep up the good work!

Damian

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Hi Damian,

First - thank you for your good words about me and Unitronics!

In short - your mail forced me to re-check my mind about the spec. I'll rise this again to discussion and I hope I'll succeed to convince our R&D to publish the expansion cable data. Your arguments are very helpful in this case.

I'll let you know the final decision ASAP.

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  • 7 years later...

 Hai all,

I am having the same type of issue.. Sorry for asking here.. Already i posted my question in separate thread.

My problem is:

I am using V350 controller with V100-17-ET2 Ethernet module in order to communicate with one additional HMI. It is working fine with a short cable (2 to 3meter). But when i connect long cable, more than 5 meter, even indication LED itself not working. The same cable is working fine between my PC and HMI. But not working between my PC and V350 controller. Please advise me..

Cable Type used: Twisted pair CAT 5e cable.

Regards,

Abilash

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