Hints and Tips for the MaPMT teststand

The DAQ does not run because of QDC communication error ?

You need to open up Labview (Automation and measurements shortcut) and open the communication.

• Open the devices and drivers tab
• Right click the VXI system 0
• Restart device 277 - the QDC (V792QDC) and also 275 CAEN (275V2288 CAENET) controller

When I run the DAQ the firmware version is zero and the DAQ just prints ---- many times ?

• The communication is faulty - check the crate is open and relaunch the communication as above.
• If operating correctly 2052 should be printed for the firmware version

Visual C++ gives errors and does not build the project

• You can only have one instance of the project running at once. If multiple instances run, Visual C++ gives strange warnings

When I run the DAQ it prints 'Buffer is not empty and not full'. Is this a problem ?

• Good this is normal

Where is the DAQ project

• It is in D:s1139056\first year work\QDC-code
• Then open up the project final for visual C++ (LowReg_MSVC)

Where is the stepper motor code ?

• It is in D:s1139056\first year work\stepper motor
• Then open up the project final for visual C++ (LowReg_MSVC)

The setup is noisy ? What do I do ?

• The stepper motors introduce noise. Turn them off when you take data !
• Check the grounding of everything

The pedestal and signal are not well separated by a valley

• Check the LED voltage is low
• Check the gate width - a value of ~30 ns seems ok
• Check the position of the gate relative to the signal. It should ~ 10 ns inside the gate. This seems quite critical

What voltages should be applied on the LEDs

• The right should display should read 5 V
• The left should be adjusted to have mainly single photon signals on the scope. ~ 3.2-3.5 V seems optimal

Example pictures from the setup

	Screenshot of gate and signal relative to gate on scope	png
	Fit of the signal on a partially illuminated pixel with the gate above	png