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Hi!

Im currently working on a project with a Vision 130 OPLC. In my application, the people interacting with the HMI, have to press the keys many times, specifically the arrow keys and the ENTER key. I'm worried about the lifespan of the keypad and i dont want it to damage.

As a solution for this, I've tought of having external buttons connected to the INPUT port of the PLC, and using them (in software) to act as the keys in the HMI keyboard (see attached image). However, I'm using a List of Text as Keypad Variable Entry, and whenever i go into keypad variable entry mode (blinking), the external buttons dont work as the keys anymore. I want to know if i'm doing anything wrong or if there is a better way to override the keypad keys.

Thanks In Advance 

Juan 

 

Override_keypad.PNG

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Hi Juan

You should use a positive transition contact instead of using an input directly on the SB 53.

With the I0 connected directly as shown SB53 will press multiple times (every scan of the PLC) as ling as the input is on.

Regards

Denis

 

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Hi Denis

Thanks for your help!

Unfortunately my problem goes on, even if i replace the direct contact with a positive transition one. For example, to enter a keypad variable entry, i usually have to press ENTER twice, one to be able to enter the value, and another one to confirm. With my external button, i can "press" the first ENTER without problem, but i can't confirm the value, in ohter words, i can't "press" the second ENTER. Same thing happens with the arrow keys, 

 

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Juan,

Check out the following:


http://www.unitronics.com/knowledgebase/visilogic/knowledgebase/visilogic/Displays/Display_Variables/How_Keypad_Entry_Variables_Work.htm

http://www.unitronics.com/knowledgebase/visilogic/knowledgebase/visilogic/Displays/HMI_Displays/HMI_SB_and_SIs.htm

I think you might be able to use SB 32 and SB 30 with the input to get the variable entry to complete(second press of enter key). You may be limited to 1 variable per screen though, I'm not sure as I've never tried this.   

--| |-- --|P|-- --( )--
 SB32    I0     SB30

Edited by Cam
spelling

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Hi Cam

Thanks for your help

I was trying your solution, but apparently SB32 and SB30 dont activate ever, even in a simple ladder code as the one in the picture

Also, by doing what you suggest will i be able to use the arrow keys as well in the variable active mode?

 

sb_doesnt_activate.PNG

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Are you wanting to use JUST the external pad, or do you still want to have BOTH methods concurrently active?  I think this is important, it might make the programming easier.  Have a screen where you can choose which method, before you get to the settings screens.  It then alters methods considerably.

cheers,

Aus

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Hi Juan,

to clarify this, I need to do some testing.  Pls give me a day, can't do it now.  Someone else is welcome to look at this idea if they have time at present.

cheers, Aus

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On 17/02/2017 at 4:02 AM, Juan Castrillon said:

buttons connected to the INPUT port of the PLC,

What exactly do you mean by this?  Using 4 digital inputs for BCD?  Using the serial port?

cheers,

Aus

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OK.  Still confusion.  I'm assuming you are talking about having your push button "1" connected to Digital Input (DI) 1.  Then your button 2 on DI 2 and so on.  This will use many of the inputs, which is  OK if you have them to spare.  You saying "port" in some ways means the serial connection socket, hence my question.  There are other ways of doing this, but.........

Before I go any further, have you considered using a cheap touch screen computer running Remote Operator, directly linked to the PLC?  In some ways this will be the easiest method of the lot as you can use the inbuilt number entry methods in Visilogic etc, but via a touch screen instead of the membrane keys.   You may end in similar costs by the time you cost out keypads etc doing it the other way.  You can find RO here to trial it:   http://unitronicsplc.com/Download/SoftwareUtilities/Remote Operator V1.0.67.zip

In the same thinking, maybe go up a PLC model to one that has a touchscreen as standard?

cheers,

Aus

  • Upvote 2

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OK, in the meantime as well, check these links out to get ideas on other ways you can possibly go.  These are just some of the methods that keypads can be interpreted into the PLC, saving on the number of inputs.  You can consider them all during thinking about how you want to do things.

For the idea of keypad matrix:   https://www.sparkfun.com/products/8653    (look at all the pictures on the page, one explains matrix)

Taking it one step further and making it BCD:  https://www.rapidonline.com/rapid-keyboard-encoder-project-kit-70902

This pdf (from the above page) explains it  https://www.rapidonline.com/pdf/70-0325.pdf

Another way:   https://stevenengineering.com/pdf/18KP_612A.pdf

cheers,

Aus

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Hi Aus

Thanks for all your suggestions and your help

After contacting Unitronics, i found out that the lifespan of the keyboard is pretty good (Aprox. 1 Million Clicking Cycles), and also that the HMI Keyboard is easily replaced. With this in mind and seeing the relative complexity of the solutions, i think i will just leave the keyboard from the HMI

Thanks again adn Sorry for wasting your time

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