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Messages - Hminx

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1
Technical support / Re: PWM issues
« on: July 06, 2024, 12:53:06 AM »
Thanks Support    That helped
Next issue is that I'm trying to run two PMW outputs concurrently controlled by two different custom functions the problem being that i cant get the two output s to operate at the same time, the second  out put wont operate until the first has completed its pulse train  [ can combine both outputs into one custom function but this becomes a bit clumsy and difficult to adjust


2
Technical support / Re: PWM issues
« on: June 02, 2024, 02:06:41 AM »
thanks for that
I have attached a shot of the pulse train at the  initial movement of the actuator  the 35% duty cycle is jitter to remove stiction the 90% is to start the actuator moving,  as it nears the required position  i would like to reduce the duty cycle to about 45%
The black line on the attachment shows the percentage of modulation I find it odd that it is varying so much, it also is obvious by looking at the pulse train so is this just a case of ' what ya sees is what ya gets ' with a T100MD
Also why does the PWM 1 output continue with start contact open, I need to hit reset to turn it off.

Appreciate your help
Cheers Pete

3
Technical support / PWM issues
« on: May 28, 2024, 02:25:18 AM »
Hi All
I'd appreciate any thoughts on an issue I'm having with a PWM function on a T100MD that I'm using in the development stage of a project which will shift a truck's AMT type  transmission directly to 5th gear. I need to position the gear selector actuator selector opposite 5th gear gate. I'm trying to reproduce to factory pulse train.
The problem is that the amount of PWM seems to be difficult to control for some reason. When Start contact closes the output 7 pulses at 500 hz 90% PWM but wont turn off when start contacts open and continues with the pulse train

                                                 Start         Clk:.05s                                                                                     cf  1
                                             ----II------------II--------------------------------------------------------------------{dCusF}

Function 1
' set pwm level for side shift function   
 SetPWM 1,A,500

    Function 3               
   if testio (r1) = 1
   then
   A = DM[1]
   else A = DM[2]
   endif
   
 
  if testio (r2) = 0
  then DM[1] = 0
  else DM[1] = 9000
  endif

  if testio (r2) = 0
  then DM[2] = 0
  else DM[2] = 3500
  endif


Not sure if this make sense, I know I've only shown a small part the program

Cheers Pete

4
Technical support / Re: PID control of two contradictory PWM signals
« on: February 27, 2024, 11:49:17 PM »
Hi Gary
Thanks for that, what you suggest makes perfect sense and should do the trick.
i will try that as soon as my replacement FMD1616 turns up as yesterday when I turn the machine on the PLC refused to respond for a while
then powered up the first four outputs plus RTC, pause, and error LEDs   lit up, plus it would no longer communicate  :(   Unlike the old T100MD
series these aren't easy to plug in a replacement chip and get it back into service maybe a marketing strategy  ;)
 Cheers Pete

5
Technical support / Re: PID control of two contradictory PWM signals
« on: February 22, 2024, 12:25:55 AM »
  Thanks for the feed back, I thought that this may be the case but was hoping for an easier work around, but such is life  :)
FYI the two PWM  signals is quite common on heavy automotive diesels, from the foot throttle to the engine ECU .   Normally we would use the auxiliary external throttle input for engine speed control, but this is not an option in this case.

6
Technical support / PID control of two contradictory PWM signals
« on: February 19, 2024, 01:08:18 AM »
Hi all

Been a few years since last used trilogi stuff but have a few up coming projects that I plan to use FMD1616-10s. The issue I'm stuck on is
how to control the  speed of an engine powering a large vacuum pump, the input signal uses two PWM signals acting together

   1.        Idle - full throttle           81 - 27 %  PWM     @ 5v  200 Hz
   2.        Idle - full throttle           17 - 73 %  PWM     @ 5v  200 Hz

The  vacuum pump is direct driven at engine speed, 1400 rpm and in this case, the speed signal at this speed is 23 Hz, and scoping the throttle signals while operating the throttle manually indicates signal 1 at about 53% and signal 2 at about 46%.  Ssooo.... what I need to do is work out some method of PID control over two control signals that move in opposite directions.

I would be quite willing to have a crack at sorting out a single channel control but the two opposing signal thing is a bit beyond me so any help would be greatly appreciated

Cheers Pete

Oh by the way, I assure you I'm not a student asking some one to do an assignment I should be doing myself  ;)





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