Why do industrial panel manufacturers use resistive touch ?

[JesperMP]

Been thinking about this, just curiously mystified.

The industrial panels that I know of all use resistive touch, rather than kapacitive touch.
Now why is that ?
I can only think of disadvantages with resistive touch, especially in an industrial environment.

The touch function is by a plastic film over the glass (or plastic). This film is quite sensitive to damage and wear. Use it with a sharp object and it is busted. Even if it survives, it gets worn over the time. I have seen lots of panels where the touch film has become completely dim and opaque where the operators press most frequently.
On my smartphone I have a glass touch screen that is remarkably resistant to scratches, and even after some serious abuse that has left some scratches, it still works perfectly.

Just curious ?

[osmanmom]

Manufacture more clever than us.

If they using capacitive technology the possibility to be sue by end user are high.

[JesperMP]

If they using capacitive technology the possibility to be sue by end user are high.

Err... why is that ?

[JDCROCKETT724]

I agree with you Jesper. I have seen the plastic get so bad that there were dead spots on the HMI from so much use. I have seen HMI panels that have just the glass as a touch screen and the sales guy was toting how resilient it was. Poked it with a screw driver and such. It was an Eaton HMI I believe with infrared touch screen technology. Don't ask me how it works, but it looked clean.

[JesperMP]

The infrared variant I believe is with small lamps and receivers on the edge of the screen. Similar to a light curtain.
Neither resistive nor infrared can do multitouch.

Thinking how great capacitive screens are (especially gorilla glass), I think that all other methods are dead or should be dead.

[JDCROCKETT724]

I just went to a siemens training event and they are coming out with panels that support multi touch. I couldn't remember if they were hmi's or touch PCs

[JesperMP]

Originally Posted by JDCROCKETT724

I just went to a siemens training event and they are coming out with panels that support multi touch. I couldn't remember if they were hmi's or touch PCs

Thats interesting.
Could it have been the new "basic panels 2nd generation" ?
I have tried to find out if they use resistive touch or not but haven't been able to find anything.

[JDCROCKETT724]

here is what I found on siemens multi-touch
https://www.automation.siemens.com/m...ame=multitouch

[JesperMP]

Ah, those are just displays. To be used in conjunction with a PC or other device to drive them.

[mts5096]

I bet price and availability are two big reasons why resistive touch persists. Smart phone manufacturers deal in enough volume to have a lot of pull in those areas. Though it seems that the price difference isn't so large anymore, so perhaps it's just historical inertia at this point.

Also, resistive touch screens are more reliable when using gloves, and you don't get spurious touch inputs when a drop of water gets on the screen.

Just my two cents.

[JesperMP]

Price and availability. I guess so, but I use an industrial panel because I want extra tough industrial reliability, not less reliability. I dont want to get a slightly less expensive panel with an unreliable touch screen. There is a discrepancy with what you get and how it ought to be.
Ah, gloves. Can have small metal chips in the fingertips from working with various tools.
Instant touch screen death !
IMO you just cant win with these resistive touch screens.

[mk42]

I had always heard they used resistive touch panels so workers could wear gloves, or use anything a stylus. Capacitive needs either special gloves or a bare finger. I'm not sure the that's the real design reason or just a marketing excuse, though. Perhaps resistive is just cheaper, or capacitive has trouble in some areas with high EM noise?


JDCrockett is right, the new multitouch from Siemens is a flat panel monitor, not an HMI panel. I think it currently is only 19", but I would assume that they would be planning to roll it out for more sizes, and hopefully eventually to the panel PC's and maybe even HMI's. I saw a demo where Siemens was touting the ability of the screens to not sense fake touches like oil/water splashes. I think they were saying they could sense 9 or 10 fingers, but I hope wee never get gestures that complicated....

I know the WinCC 7.2 supports some level of multitouch now, and I think WinCC Advanced v13 does as well, but I'm not sure what the features actually are.

According to the basic panel gen 2 manual, they are still resistive touch, like the other HMI's:
http://support.automation.siemens.co...ew/en/90114350

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Looks like I take too long typing. That's what I get for doing this on a mobile device....

[JesperMP]

Originally Posted by mk42

I had always heard they used resistive touch panels so workers could wear gloves, or use anything a stylus. Capacitive needs either special gloves or a bare finger.

I think you are right about that.
Problem as I see it, gloves is no guarantee that the touch film does not get damaged, and when you use a stylus sooner or later some idiot thinks his screw driver is just as good.

Originally Posted by mk42

According to the basic panel gen 2 manual, they are still resistive touch, like the other HMI's:

You are right, I guess it was too much to hope for.

[RussB]

Some are turning to Capacitive, I'm guessing because of cost. They just may end up regretting it if sales are lost because their favorite gloves no longer work.
See this as a reference.
http://www.plctalk.net/qanda/showthr...354#post588354

[OkiePC]

http://www.youtube.com/watch?v=k5OjO8KnZno