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Ljuba

OPC Communication Slow

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Hi,

I have two Jazz JZ20-J-T40 PLC-s, and one V130-J-TR20 PLC.

I am using zView SCADA.

I tried to connect them via Ethernet by using switch, but I cannot use two different PLCs  on this SCADA.

Then i tried to connect them to SCADA via uniOPC, but communicating is just too slow.

I have just one bit that goes from 0 to 1 in 0.5 seconds, and back to 0 in 0.5 (1 second pulse), just for testing, still it's too slow. It runs normally for like 2,5 seconds, and then just stops, and changes in 4-10 seconds, or just freezes for 2-3 minutes, and then changes.

My PC Spec are not in the way of this, I am sure of that, i have tried it on my weakest and strongest laptop, still exactly the same results, too slow with just one bit for each of the PLCs, that is 3 bits total.

Does anyone had the same problem, is there a way of fixing this?

Regards

Nikola Ljubinkovic

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I did have performance issues with UniOPC, it would overload CPU when large number of tags is being sampled, for this I switched to ModbusTCP. But it would work just fine with small number of tags.

I never worked with ZView, what are communication settings for this SCADA? Like "Query pause" or com settings for channels (if you can switch communication to different channels they would run in parallel, while PLCs on single channel get pooled in sequence which tends to be slow). Are there any settings for tags like "store values" (for remembering historic values for graphs), I noticed those values get less omitted than those that are not keeping a record.

Anyway, having instant response for SCADA with less than 1 second delay is not realistic. Like your 0,5 second flashing bit. You need different type of communication protocol to catch such a change.

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Thanks for response Isakovic, 

I have tried to find setting like that on my SCADA, but i didn't have any luck. I will keep trying, but it seems like a dead end.

Because of this problem, I am now trying to make my Vision 130 PLC read other two Jazz PLCs, and write them.

Goal is to my V130 PLC communicate with SCADA, and other two Jazz PLCs.

Problem with this is that if my V130 stops working for any reason, SCADA will no longer see any of my three PLCs, although Jazz PLCs keep working.

Also this means that I will not se if my Jazz PLCs are broken if my V130 stops working.

Anyway, this is my last option, although I don't like it.

Can you give me some advice in order to make this (V130 master Jazz Slave) kind of connection work?

Also, is there something that I should make on my Jazz, or V130 in order to get faster communicating with SCADA?

Regards

Nikola Ljubinkovic

 

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You can use Modbus for Vision-Jazz communication. Jazz has only one Ethernet port but it can be configured for both Modbus and PC connection (only one active at a time).

7 hours ago, Ljuba said:

Also, is there something that I should make on my Jazz, or V130 in order to get faster communicating with SCADA?

Put memory segments you need to read in sequence (MI0, MI1, MI2...).

Contact support for additional help to make SCADA work with all PLCs, it must be something trivial that you overlooked. I always received fast and useful advice Unitronics support.

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