Bandpass Test

Purpose

This test is intended to detect hardware defects such as ground shorts by checking for noise in the course channel power spectra. The test assumes no analogue inputs to the TPM and verifies the integrated channel power is flat. For data acquisition to function correctly, the 40GbE interface on the TPM must be working, as well as the link to the LMC destination. For these tests the CSP and LMC destination should be the same network interface, routing all traffic to the server running the tests.

NOTE: For data acquisition to function correctly, the network interfaces on the TPM must be working, as well as the link to the LMC Integrated destination. The LMC Integrated destination must be configured to route traffic to the server running the tests. For all tests the simplest option is for the CSP and LMC destinations to be the same network interface, routing all traffic to the server running the tests.

Methodology

  1. DAQ receiver is configured and initialised with the required UDP port and network interface.

  2. Channeliser truncation is disabled for the test to acquire the raw channeliser output.

  3. The integration time of the course samples on the FPGA is configured as requested. This defaults to 1s integration which appears to be the most reliable at finding hardware faults.

  4. If the TPM has preADUs fitted, their attenuation is set to 0. Maximising any noise that may be present.

  5. Integrated course channel data is captured by the DAQ receiver for all Tiles.

  6. For each antenna, channel and polarisation, the power is evaluated against the average power across all channels. Channel 0 is ignored.

  7. The integration time is reverted to its value before the test began.

  8. The channeliser truncation is reverted to its value before the test began.

  9. Failing channels are logged and at the end of the test faulty TPMs are reported.