CREVIS FnIO-S ST-121F Is this an AS-i device?

[Skogsgurra]

I have been given the impression that this is an AS-Interface (the yellow profiled flat cable) device. But I think that either I or someone else makes a mistake. So, I need a few second opinions. Maybe also an explanation how the mistake came about.

And, while we are at it, is this I/O family recommended in plants with lots of PWM VFDs and long cable runs?

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[Skogsgurra]

Sorry - that is a non-question.
Someone goofed.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[controlsdude]

The Asi cable does get PWM drive noise on it, so routing is important. Seen it in past. The network does have noise immunity built in but like all networks the routing is important where cabling of PWM drives are close by. Yellow flat cable is ASi communications cable.

 

[Skogsgurra]

Yes, dude. We noticed that today. And worst of it all is that the user hadn't read the manual. So he didn't connect the "center tap" (midpoint between A+ and A-) to ground. There are several AS-i circuits in this installation. There are also reepaters. None of them was connected to ground. We did that and it seems to be running a lot better now. We were waiting for production to stop so we could disconnect things that we want to bring home again, but had to give up because the process is just running and running and God knows when it will stop next time.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[controlsdude]

I did go thru the training a few times with distributors on Asi. So here is a list of things to look for that pertain to length.

Network Length
100 meters no repeaters
200 meters with repeaters
800 meters max with repeaters and terminators
Class 2 voltage/current levels situation
2.8A areas definitely complys with class 2
4.0A areas maybe complys with class 2
8A areas does not comply with class 2

Now the cable lengths above I have different opinions on max of 800. The 800 meter is counting all lengths (star type connections) Terminators are also important on where they actually go in system. Example put terminator at max length before the asi cable goes into repeater.

There should be some either web based interface for the gateway scanner. I would load up that and see where the errors are occurring. The gateway scanner display might be a little cryptic to understand what its saying. Thought the gateways I saw had built in Ethernet switch in gateway for that purpose to look at the gateway easier.

 

[controlsdude]

Here are some more notes about lengths and where terminations should go, which is important if you have errors.

Cable Length 100meter limit for each segment
Cable Length is the total of all star, daisy chains, and trunk lengths within segment
Repeater is used when continuing the network to a different segment
T terminators are used at the maximum distance from the gateway or before the next repeater
T terminators are put at the furthest end of the segment and extend segment to 200 meters
An additional power supply needs to be added to each segment and right after the repeater
Power Supply needs to be on opposite end of the T terminator.
The maximum delay of each device is 156micro seconds