William_B

Setting the input filter time for HSC inputs are required when using TIA Portal V13.. regardless of which firmware version you have. Watch out.. Specific inputs / outputs have specific pulse speeds that it can handle. Older firmware versions also limit which combinations you can use.

Kal.A

Hello Gentlemen!

I've routed the output pulse of a PWM into the diigital inputs of a 1214C DC/DC/DC v3.0 to test HSC and also to simulate a quadrature encoder (I travel a lot and it's easier).
If I have the pulse at any higher than 20 Hz the LED on the digital inputs will not even light up at all. I tried using lower duty cycle and that helped a little but I still can't get anywhere near the specification of the DI which is anywhere between 30-100 kHz depending on the input.
Then I calculated the 0.2 Ms of the filter which comes out to 5kHz.

So how fast are the digital inputs with and without HSC enabled?

There are some pieces that bothers me..
1. simulate a quadrature encoder
How do you intend to get two outputs to pulse to simulate the "quadrature" nature. Does FW3 give you this option?

2. he digital inputs will not even light up at all
There should be a glow on the input indicator LED. Not bright.. but there should be one. If there is none then there is a voltage issue. Take Jacek's notes seriously.

3. lower duty cycle
The HSC does not like PWM signals so much. Best if you set up a PTO - configure motion control and use the JOG function.

Your thoughts?
w

 Thanks William.

By writing "Specific inputs / outputs have specific pulse speeds that it can handle." do you mean the minimum  length the pulse needs to be high to be recognized by the input? Is it  0.2 ms without HSC and 800 ns with HSC?  Please clarify what you meant.

I experimented with two things, PWM directly fed to single phase HSC and PWM fed into a normal input and used logic to simulate the AB encoder which is obviously  limited by the input filter and the logic+ timers used to simulate the 90 degree phase shift. (PWM into an input>simulate AB encoder>fed into HSC set up for AB-4X )

In both cases I did not get the speeds I expected. And when I said the digital input did not light up I meant the LED indicators (is there anything else?) . I kept lowering it down till I got the LED to stay on (obviously the pulses are too fast to see it flash)

None of this is critical and is all experimental but it through me off and I am using it to understand more of the working of the hardware.

I will certainly try Jacek's and Marko's suggestions and will also try your suggestion of using PTO with JOG function.

Thanks a lot everyone this has been very informative.

Kal