Digital output

Discuss issues and ideas you have to configuring displays with PowerVision
liulanger521
Posts: 10
Joined: Fri Oct 08, 2010 7:31 pm

Digital output

Post by liulanger521 » Wed Dec 22, 2010 2:58 am

I hope use the digital output in my application, now I can see the parameter "IO.Digital Out" for digital output, but I can't find the document that how to use it? Is it used like this:
IO.Digital Out=1or true, then it output 24V. Could it output proportion voltage
Hope you could offer example?
jpurdum
Enovation Controls Development
Enovation Controls Development
Posts: 153
Joined: Mon Jun 21, 2010 11:19 am

Re: Digital output

Post by jpurdum » Wed Dec 22, 2010 3:18 pm

That database variable is actually feedback to tell you how the output is set. To set the I/O high or low, call an action from a state in a state machine from the application "IO" where you will find two possible actions - "Output High" and "Output Low".
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mbowdich
Posts: 209
Joined: Tue Oct 05, 2010 10:54 am

Re: Digital output

Post by mbowdich » Thu Dec 30, 2010 12:57 pm

Just a question to clarify the issue, since the original post included an attempt to source 24V.

Isn't the PV750 only rated for sinking power (ground) on the digital output?
jpurdum
Enovation Controls Development
Enovation Controls Development
Posts: 153
Joined: Mon Jun 21, 2010 11:19 am

Re: Digital output

Post by jpurdum » Mon Jan 03, 2011 5:40 am

Ah yes, thanks for being so observant! I did miss that.

Correct, the output will not source 24V - however on the PV750, I don't believe it's an open drain either. I'll forward this on to someone with better info on the digital out on the 750.
shuhn
Posts: 5
Joined: Mon Jan 03, 2011 9:53 am

Re: Digital output

Post by shuhn » Mon Jan 03, 2011 10:15 am

The digital output on the PV750 is an open-drain output which will work with 24V applications. It is designed to sink 500mA and it is protected up to 32V.
Scott Huhn
Senior Electrical Engineer - Displays
Enovation Controls
liulanger521
Posts: 10
Joined: Fri Oct 08, 2010 7:31 pm

Re: Digital output

Post by liulanger521 » Mon Jan 03, 2011 7:34 pm

In pages 16 of the PV750 Installation Operation Manual, I see the following image:
Is it means that I only can get the 24V from the external supply, then the PlugA Digital Out is the ground, when we set the output high, the buzzer will ring, or else we set the output low
the buzzer will not ring
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shuhn
Posts: 5
Joined: Mon Jan 03, 2011 9:53 am

Re: Digital output

Post by shuhn » Tue Jan 04, 2011 7:54 am

Correct. The load, in your case it sounds like a buzzer, must be supplied with voltage from a battery or some other external power source. The digital output on the PV750 then provides the ground for the load when the output is turned on, thus energizing the load.
Scott Huhn
Senior Electrical Engineer - Displays
Enovation Controls