TDCPix Test Setup at CERN
Instructions for connecting to and using the TDCPix test setup in building 14 at CERN.
Connecting
The chip is connected to tdcpix-testbench available on the CERN network. For outside access, connect via lxplus.
GrafAna
Power supplies and other quantities are being pushed to GrafAna setup on the test computer. To access from outside of CERN, you need to create a tunnel via lxtunnel.
ssh -L 3000:tdcpix-testbench:3000 lxtunnel.cern.ch
Point your browser to http://localhost:3000 or directly the Monitoring Dashboard.
Power Supplies
| Power Supply | Voltage | Current |
|---|---|---|
| Chip Power (PLL Disabled) | 3.6V | 1.97 A |
| Chip Power (PLL Enabled) | 3.6V | 3.26 A |
| Sensor Bias (Testing) | -10V | around -60 nA |
Code
A git repository with the code is available at https://gitlab.cern.ch/bilpa/TDCPix/tdcpix-test-bench. A central clone exists in the shared account under /home/gtk2021/projects/tdcpix-test-bench.
Installation
Make sure you have an older version of ROOT (v5.34.38) available under ``. The setup script looks for it in this location. If you do not, you can compile it following:
git clone https://github.com/root-project/root.git
cd root
./configure --prefix ${HOME}/opt/root_v5.34.38
make
make install
Now you can compile the tdcpix-test-bench project. Note that you'll have to source the setup.sh in every new session when using the testbench. It setups all the necessary paths and configuration variables.
git clone ssh://git@gitlab.cern.ch:7999/bilpa/TDCPix/tdcpix-test-bench.git
cd tdcpix-test-bench/
source setup.sh
cd .libs
./mklinks.sh
cd ..
make
If everything compiled successfully, you should see executables available under TDCPixReadOut/Tools/bin/.
Running
Always source setup.sh inside a new shell to setup all of the necessary paths.
Most of the key DAQ programs are located inside TDCPixReadOut/Tools/bin/. All commands below are executed from inside that directory, unless otherwise stated.
The InterfaceController must be running at all times. If the DAQ gets stuck, start by restarting it (kill + run again). To start it, run the following and leave it in the background:
./InterfaceController reset
Something needs to be initialized after the interface controller is running.
./initialise
./PLLEnable 1
./en_daq
The PLL needs to be enabled when running tests via the PLLEnable 1 command above. When not running tests, please disable it (first argument 0) as this increases the chip power usage considerably.
./PLLEnable 0
Power Supply Control
The chip power and sensor bias power supplies are remotely controllable. The labRemote framework should be used for controlling them. There is a monitoring program running 24/7 with data pushed into InfluxDB. See the section on monitoring on how to visualize this information in GrafAna. The labRemote takes care of access control when changing settings.
Documentation of labRemote is available in the project itself. For our purposes, you can use the central installation under /home/gtk2021/labRemote. The following commands should be ran from that directory. An equipment configuration file is available under /home/gtk2021/labRemote/input-hw.json.
There are two channels defined.
| Channel Name | Description | Comment |
|---|---|---|
Vpower |
The chip power provided via a TTi. | Keep this on, unless you really really need to power cycle. |
Vbias |
The sensor bias provided via a Keithley2410. | Make sure the chip power is ON when applying it. |
The following command turn on chip power. To power-down, use the power-off argument.
./build/bin/powersupply -e input-hw.json -c Vpower power-on
The following command enables a sensor bias of -10 V.
./build/bin/powersupply -e input-hw.json -c Vbias power-on
./build/bin/powersupply -e input-hw.json -c Vbias set-voltage -- -10
To remove sensor bias, run the following.
./build/bin/powersupply -e input-hw.json -c Vbias set-voltage -- 0
./build/bin/powersupply -e input-hw.json -c Vbias power-off
Common Errors
/tmp/.dh/channel_data_0 could not be opened for writing.
Starting InterfaceController can result in the following error.
Starting Packet Server:
setting up file: /tmp/.dh/channel_data_0
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_SetupSinkFiles, line 345: Message = unable to create named fifo: /tmp/.dh/channel_data_0
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_SetupSinkFiles, line 346: Message = Permission denied
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_SetupSinkFiles, line 360: Message = /tmp/.dh/channel_data_0 could not be opened for writing.
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_SetupSinkFiles, line 361: Message = Error message = Permission denied
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_SetupSinkFiles, line 362: Message = Possible reasons: file doesn't exist; permissions are incorrect; or another process has already opened the file.
TPS_ERROR: File = src/DownstreamDataHandler.c, function = DownstreamDataHandler_Construct, line 126: Message = setup of temporary directory failed.
RG_ERROR: NULL pointer returned from allocation StartPacketServer (file src/Common/InterfaceController.cc : 302)
RG_ERROR: Non-zero return value received (-1). Message = InterfaceController::StartPacketServer().(func main file src/InterfaceController.cpp : 104)
If this occurs, check the permissions of /tmp/.dh. Sometimes they are reset to be rw only the owner. This has to be manually fixed either by the owner or by someone with sudo access.
chmod go+rwx /tmp/.dh
chmod go+rw /tmp/.dh/*