Strange output

[DAlgie]

Hello, when using a T100MD-1616 PLC, I am trying to get it to output PWM to a small servo. I have followed the book letter by letter. I have the output as a sink, but never get any kind of output signal at all. It all runs ok in the simulation. I never see the LED on the board light up either. Anyone can tell me what my ladder rung should have on it that I'm missing? I use a slow clock signal to time it between another rung, and output with a custom function with the PWM statement in it.

[support]

If you don't connect anything to the PLC output, and then execute a statement such as SETPWM 1,5000,5000, you should see the output #7 light up partially. Output 7 is PWM 1 and output #8 is PWM2.

Once you verify that the PWM output is working properly you can then proceed to connect it to your load and it should function as expected.

[DAlgie]

Output 7 is PWM 1?? Gee, that would explain why the LED on 7 was lighting up, I was connecting to channel 1!! Thanks, OK, I'll go try it now.... !!

[DAlgie]

Yes, that worked, thanks. A question with the PWM, I need a 1 to 2 ms pulse, I have set the PWM at 62 Hz, and use a pulse between 90 to 160, what should the syntax be, do I need a zero in front, must it be four digits, etc.

[support]

The PWM output only support 8 frequencies. One of them is 63 Hz so you can execute:

  SETPWM 1, 5000,63

That should give you a square wave pulse output at about 63 Hz and 50% duty cycle.