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Entry  Fri Feb 22 11:46:17 2013, Yury Golod, DRS4 trigger, different polarity 
    Reply  Fri Feb 22 11:56:57 2013, Stefan Ritt, DRS4 trigger, different polarity 
Message ID: 220     Entry time: Fri Feb 22 11:56:57 2013     In reply to: 219
Author: Stefan Ritt 
Subject: DRS4 trigger, different polarity 

Yury Golod wrote:

I need to synchronize two signals. These signals have a different polarity.

I can set triggers on different levels. But I can't set different polarity of triggers.

Now I can set (T1 and T2), I need to set (T1 and (not T2))

Is it possible?

 

           

 

d->SetTriggerLevel(-0.4,0.4,0.0,0.0,false);

d->EnableTrigger(1, 0);  // Enable trigger

d->SetTriggerSource(1<<8 | 1<<9);  // T1 and T2

 

file DRS.cpp:

int DRSBoard::SetTriggerLevel(double voltage1,double voltage2, double voltage3,double voltage4,bool negative)

{

      SetDAC(fDAC_TLEVEL1, voltage1/2 + 0.8);

      SetDAC(fDAC_TLEVEL2, voltage2/2 + 0.8);

 

There is no way to select different polarities, it is not implemented in the firmware. Like your digital oscilloscope has also only one polarity switch.

The only way to do it is to use a (passive) inverter, so that you have two signals of the same polarity. Something like this:

http://www.phillipsscientific.com/pdf/460ds.pdf

 

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