Changing sample frequency of acquisition

Supporting 2.7 and 3.2+
YLM
Phidgetsian
Posts: 9
Joined: Mon Nov 18, 2019 9:38 am
Contact:

Changing sample frequency of acquisition

Postby YLM » Mon Nov 18, 2019 9:53 am

Hi,

Maybe stupid question (hope someone did not answer in the topic, I did not find it...).

I am using the python code automatically generated for the PhidgetBridge 4-Input.

Code: Select all

from Phidget22.Phidget import *
from Phidget22.Devices.VoltageRatioInput import *
import time


def onVoltageRatioChange(self, voltageRatio):
   print("VoltageRatio [" + str(self.getChannel()) + "]: " + str(voltageRatio))

def main():
   voltageRatioInput0 = VoltageRatioInput()
   voltageRatioInput1 = VoltageRatioInput()
   voltageRatioInput2 = VoltageRatioInput()
   voltageRatioInput3 = VoltageRatioInput()

   voltageRatioInput0.setChannel(0)
   voltageRatioInput1.setChannel(1)
   voltageRatioInput2.setChannel(2)
   voltageRatioInput3.setChannel(3)

   voltageRatioInput0.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
   voltageRatioInput1.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
   voltageRatioInput2.setOnVoltageRatioChangeHandler(onVoltageRatioChange)
   voltageRatioInput3.setOnVoltageRatioChangeHandler(onVoltageRatioChange)

   voltageRatioInput0.openWaitForAttachment(5000)
   voltageRatioInput1.openWaitForAttachment(5000)
   voltageRatioInput2.openWaitForAttachment(5000)
   voltageRatioInput3.openWaitForAttachment(5000)

   try:
      input("Press Enter to Stop\n")
   except (Exception, KeyboardInterrupt):
      pass

   voltageRatioInput0.close()
   voltageRatioInput1.close()
   voltageRatioInput2.close()
   voltageRatioInput3.close()

main()


I would like to set the sample frequency of the acquisition. I thought it was the 5000 but it is not (btw I do not understand what this 5000 do, when I changed it I do not see any change).
Does someone know how to change the sample frequency ? Is there a method of the Phidget22 library that I need to use ?

Thank you

User avatar
mparadis
Site Admin
Posts: 690
Joined: Fri Oct 28, 2011 12:17 pm
Contact:

Re: Changing sample frequency of acquisition

Postby mparadis » Mon Nov 18, 2019 3:47 pm

The "5000" in this case is the timeout in milliseconds for openWaitforAttachment. This means that it will try to find a voltageRatioInput channel for 5 seconds before it gives up and throws a timeout exception.

In order to change the data interval for each channel, use setDataInterval. You can find more information about this method on our api page.

YLM
Phidgetsian
Posts: 9
Joined: Mon Nov 18, 2019 9:38 am
Contact:

Re: Changing sample frequency of acquisition

Postby YLM » Tue Nov 19, 2019 2:12 am

perfect, thank you


Return to “Python”

Who is online

Users browsing this forum: No registered users and 1 guest