Uwe_A

Keyence KV-B8XTD beginners question

12 posts in this topic

I'm trying to make my first steps with a Keyence GPIO unit called KV-B8XTD connected to a KV-7500.

I'm using the KV-Studio 10 for control. The only thing I want to do is to switch an output of the GPIO from low to high.

I set the KV Studio to "Monitor", open the KV-B8TXD and set some outputs (see image)

I would assume that OUT0, OUT2, OUT3, OUT6 and OUT7 on my B8XTD are showing +5V but they don't. All outputs stays at 0V.

What is going wrong? Do I misinterpret the "I/O unit monitor" if I assume it is meant to be used for setting the output signals?

 

Uwe

 

 

KV-B8XTD.jpg

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The KV-B8XTD has sinking type (NPN) transistor outputs. This means the outputs will switch the negative side of an external voltage to a load. Once you have connected a complete circuit, you will measure +5V or +24V (whichever you use) at the output terminal when the output is OFF. Turn your output ON and you will measure close to 0V.

Mr_PLC_KVB8XTD.PNG.675fd8b8e5c27bd425e4a

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Thank you for the information!

Now I have 4,63V at OUT0 but unfortunately it does not change to 0V if I turn the output to ON.

Is this I/O unit monitor the right tool for setting the outputs?

Or do I have to set it via a Ladder program?

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Quite honestly, I have never used the I/O Unit Monitor. It may work but I prefer to use ladder, especially if the output is already programmed in ladder. I would like to give you a better answer but I find KV Studio to be very confusing at times. I believe the Japanese to English translations are very poor. It's good software with a lot of functions but I have trouble understanding most of them.

I would write a test program where you can use internal bit to drive your outputs. Then, in Monitor Mode, double click the internal bit to toggle ON/OFF.

Mr_PLC_KV_Monitor.thumb.PNG.80c9e36c09e7

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I wrote a test program with two commands:

1. "A 0" (reading from IN_0) and

2. "O 100"(writing to OUT_0).

Is that correct? (I was not quite sure how to use an internal bit to drive my output...)

I would assume that if I supply +5V to IN_0 I should see a reaction on OUT_0. Right?

 

But there is another issue: It looks like I cannot start my PLC program. If I press the "RUN / cont. scan" button nothing happens. The "PROGRAM / stop" button is still highlighted. Additionally the status bar keeps showing "- PROG" but it should switch to "RUN", I think. Can you verify?

(I set the "PROG/RUN" switch of my 7500 to "RUN" otherwise I get a message that I cannot switch to run mode)

 

Ladder.jpg

Status.jpg

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46 minutes ago, Uwe_A said:

I wrote a test program with two commands:

1. "A 0" (reading from IN_0) and

2. "O 100"(writing to OUT_0).

Is that correct? (I was not quite sure how to use an internal bit to drive my output...)

Yes, this will work for testing. You should review the manual for the different memory types. In my example I used internal bit "M240". You can use M0, M1, M2.... up to M15999 in my case. I'm using a KV-5500. The 7000 series may have a different amount of memory.

 

46 minutes ago, Uwe_A said:

I would assume that if I supply +5V to IN_0 I should see a reaction on OUT_0. Right?

No. The module is sinking (NPN). This means you supply negative to the input terminal. See the input diagram.

Mr_PLC_KVB8XTD_Input.PNG.0d65d133c72c7d9

 

47 minutes ago, Uwe_A said:

But there is another issue: It looks like I cannot start my PLC program. If I press the "RUN / cont. scan" button nothing happens. The "PROGRAM / stop" button is still highlighted. Additionally the status bar keeps showing "- PROG" but it should switch to "RUN", I think. Can you verify?

Did you perform a Transfer to PLC? It looks like you have.

Perform a Convert (Ctrl + F9) and verify no errors.

From the Monitor/Simulator menu, select Unit Monitor and verify the Error Status.

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Just now, IO_Rack said:

You can use M0, M1, M2.... up to M15999 in my case. I'm using a KV-5500. The 7000 series may have a different amount of memory.

In the case of the KV-7500, the internal bit memory is "MR" 0 - 399915. See the User's Manual - List of Devices.

 

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On 20.12.2019 at 1:52 PM, IO_Rack said:

Did you perform a Transfer to PLC? It looks like you have.

Perform a Convert (Ctrl + F9) and verify no errors.

From the Monitor/Simulator menu, select Unit Monitor and verify the Error Status.

"Convert" shows no errors.

Error Status is "None".

But the bottom line status still shows "/ PROG" even if I press "Start Monitor" (F4).

Is my PLC broken??

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1) Right click on [0] KV-7500 from the project tree and select Error Monitor. The manual states the PLC will be switched automatically to PROG mode in the case of a serious error.

2) From the Monitor/Simulator menu, select Verify with PLC/synchronize. This will make sure you have a program in the PLC.

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I found the problem. It was a faulty end unit(KV-B8XTD). After exchanging it my software(and the KV-7500) work as expected.

Thank you for your support!

Edited by Uwe_A

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Thanks for your solution.

Did you see the error at any point? You should have got some type of I/O Error if the bus side of the unit was faulty. If the output was faulty then you still should have been able to switch to RUN Mode.

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There was no error shown. And yes, I should have been able to switch to run mode, but I wasn't.

At least I was lucky finding it. The end unit was the first unit I exchanged...

 

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