Backlight off

[SRO]

Hi all,
 
Question:

•  Is it possible to turn the backlight completely OFF in Unilogic by ladder?

If I try to control the brightness by ladder;

• Actions - > "Change Brightness" and link a UINT

The help-file states:

Change Brightness
(range: 10-100)

 

When the trigger bit turns ON, the screen brightness increases to the level in the linked register. This bit is reset by the system.
If the register value is out of range:
- Lower than 10: Brightness set to 10
- Higher than 100: Brightness set to 100

So this seems to be normal behavior.
 
But if I use Uniapps -> Display & Audio;

• Sliding the brightness-slider to zero, does turn the display completely off!

According to Version Changes, this is the case since Unilogic 1.8.51, Unistream OS 1.8.9, October 2014
 
Nevertheless, it would be ideal (for me and others too I think ) if we could get complete control over the backlight, from 0-100%, by ladder.
In my application, the PLC will be present in a livingroom, controlling lights, heating, etc. Even at a percentage of 10%, the display is still quite lit up in a dark environment.
To avoid being distracted by the lighted backlight watching tv eg.. and to save the precious backlight for prolonged life,
I would like the possibility to completely turn of the backlight by ladder if the display hasn't been touched for a predefined time.
 
=> Is there a work-around without the need to open Uniapps or am I still missing something?
 
 PS. Updated the PLC and Unilogic software to latest releases, being OS 1.15.11 and V1.15.70 at the moment.
 

Thanx in advance,

 

Steven

[Flex727]

Nevertheless, it would be ideal (for me and others too I think ) if we could get complete control over the backlight, from 0-100%, by ladder.

 

Yes, please! Unitronics developers, this needs attention.

[SRO]

Flex727,

 

Thanks for the support..

 

I find it difficult to understand that it ain't possible to kill the backlight with the new Unistream-line anno 2015,

especially while all that other fancy stuff with displays (eg. the Visilogic PLC series) have no issue with this feature..

 

Really had hoped one of the support guys had responded in the meantime..

..saying this will be fixed in the next release..

 

Grtz,

 

Steven

[yehudag]

Hi Steven

 

You have a work-around for this issue.

 

1. Add a Screen named: "Screen Saver"

2. In the "Screen Saver" screen add a "Fixed Text" element, without text, and a Black background, and "Fit it to screen" (right click on the element -> Fit to screen).

3. Add to this "Fixed Text" a Action "Load/Last Screen".

4. Add a Global "Load Screen" Action to the project, bind it to a bit named: "Load Screen Saver Bit".

5. On the IsActive of that screen, add a global action that sets the back-light to 10%, and when existing that screen, you can make the back-light back to 100%

 

Now you can set this bit ("Load Screen Saver Bit") anywhere you want (Ladder, HMI, Timer).

 

 

As for the 0% in the UniApps, setting the value to 0% actually doesn't turn it off.

 

We will add this feature as a feature request, but I don't know if, and when it will be implemented.

[Flex727]

Thank you!

[SRO]

Yehudag,

 

Thanks for the feedback.

 

Your workaround was more or less already my "poor man's solution" ..

 

 

As for the 0% in the UniApps, setting the value to 0% actually doesn't turn it off.

 

What do you mean by "actually" ?

Because I think I do can turn off the backlight through UniApps, this is 0% I believe. (screen goes completely black, not like the 10% treshold)

Although my wife and kids complain about a high pitch frequency noise if this is accomplished. Sadly, I don't hear this noise at all.

 

Can this be veryfied by someone?

If needed I can provide some video to demonstrate this behavior.

 

Grtz,

 

Steven

[Saragani]

Hi, on my PLC I cannot turn the screen completely off, even though I change in the UniApps to 0%.

The fact that your PLC creates a high pitch noise indicates that it is actually at 0% (One of the hardware engineers explained why it happens).

 

As far as I know, the software should protect against values lower than 5% (and you somehow managed to get a value of 0).

[SRO]

Ok, thanks for the confirmation that my logic is sound.

 

So, this rises the question why I'm able to change to 0%.

 

And, since this sounds to be some kind of hardware related, is there a risk at keeping the display @ 0% for a prolonged time?

Surely, there must be a reason why you guys aren't so fond about killing the backlight completely.

Why the 10% (5%) treshold? Why the high pitch sound when @ 0%? Is it possible to have any enlightment on this?

 

Don't get me wrong, I'm a true Unitronics fan!

Been programming the M90-91's, standard and enhanched series for 10+ years.

Just want to have a clear view on this issue..

 

Grtz,

Steven

[Saragani]

Our hardware engineers told me that you can't turn the back light totally off (you can set it to the minimum, but not off), and that the high pitch sound does not cause any damage.

You never mentioned what PLC model you have.

 

For turning the screen completely off, a command need to be implemented in the OS for turning the display (that's what is done in the Vision PLCs, when you set the back light to 0).

[SRO]

Sorry, my bad..

 

PLC is a Unistream 7"

Panel: USP-070-B10

CPU: USC-P-B10

[Erwin]

Our hardware engineers told me that you can't turn the back light totally off (you can set it to the minimum, but not off), and that the high pitch sound does not cause any damage.

You never mentioned what PLC model you have.

 

For turning the screen completely off, a command need to be implemented in the OS for turning the display (that's what is done in the Vision PLCs, when you set the back light to 0).

 

OK, about no damage, but it can become very annoying if one can hear the sound.

[Kamil]

Hi,

I'd like to re-fresh this topic.

I have US7-B10-RA28 and I need to switch off the HMI backlight in some cases

Is it finally possible? I'vetried to put #0 but UniLogic doesn't accept this. If put there UINT8 with fixed value 0 it can go w/o errors but it looks that it doesnt work.

Thank you!

Kamil

[GetAGrip]

Update - Unitronics did implement a Screen saver that turns off the back-light. It is in the configuration (near the top of the tree, just check the box and set the idle time).

Someone needs to fix this, the backlight is only good for 30,000 Hours on a lot of the units. that is only 3.4 years. Even on the 50k Hr units they are dead at 5.7 years.

Edited September 5, 2023 by GetAGrip
Add feature

[Ausman]

GaG, I know it's not the answer you want, but if it hasn't been fixed at the OS level, then perhaps a little internal work coupled to an output that is triggered by screen action would do the job properly.

[kratmel]

On 8/6/2022 at 1:55 AM, GetAGrip said:

Someone needs to fix this, the backlight is only good for 30,000 Hours on a lot of the units. that is only 3.4 years. Even on the 50k Hr units they are dead at 5.7 years.

One of my customers once requested to build a system using an Оmron HMI panel and PLC to be able to easily replace the backlight when it fails (the backlight is a separate replacement unit). With great difficulty, I managed to program such a system (it was the first time I saw an Omron panel and programmed such a controller).

My biggest surprise was that when the backlight did fail - it was impossible to buy - because the manufacturer had withdrawn it from sale (and the customer did not buy a spare when it was available). I had to program again to replace the panel with a new model.