Author Topic: MC024-020 Output Noise  (Read 4079 times)

plknapp

  • Guest
MC024-020 Output Noise
« on: October 03, 2011, 08:07:19 PM »
We have a MC024-020 PLUS+1 controller driving PVES valves.  Analog inputs are from potentiometers (Vexcitaton is 5V sensor power from controller) into Sensor blocks to PVE_A_H_S blocks to MFOuts.

Configuration is as follows:

For my application I have 6 analog inputs (C2P01, C2P02, C1P05, C1P10, C1P11, C1P12) corresponding to 6 outputs (C1P03, 04, 05, 06, 07, 08) to drive 6 PVES valves.  The one output version has input = C2P01 and output C1P03.

I have set in PLUS+1 for each Input and Output values below:

Application.PVE_A_H_S.DigiIn.PinConfig = 2
Application.PVE_A_H_S.DigiIn.PinConfig0 = 2
Application.PVE_A_H_S.Output.PinConfig = 6

Outputs.Group1.CurChgLim = 111
Outputs.Group1.DitherFreq = 0
Outputs.Group1.ReqFreq = 4000

Outputs.C2P03_MFOut1.DitherAmp = 0


I still get dither: 25V amplitude, 2.6kHz frequency and PWM varies with input voltage.

I would like a steady, non-dither output voltage to drive PVES valve.


Previous version of code had a multiplier between the sensor function and the PVES function.  This would multiply the Sensor output by +1 causing the PVES function output to range from 50% to 75%  of PVES excitation corresponding to a 0 to 100% PVES flow from port A.   Or it would multiply the Sensor output by -1 causing the PVES function output to range from 50% to 25% of PVES excitation corresponding to a 0 to 100% PVES flow from port B.

For 0 to 100% speed in one direction, PVES output is 1/2 to 1/4 PVES Vsup.  Signal is steady.
For 0 to 100% speed in other direction, PVES output is 1/2 to 3/4 PVES Vsup.  Signal is noisy.


I removed the multiplier and the noise went away.  Very strange.



Anybody seen this before and anybody have any answers?

Any and all help is greatly appreciated.
« Last Edit: October 04, 2011, 11:45:20 PM by plknapp »