Flagging Test

Purpose

This test verifies flagging of out-of-range values in the tile beamformer firmware. A channelized data pattern which should cause a specified course frequency channel to be flagged is generated at the input to the tile beamformer. In the firmware, data is flagged by setting it to the negative-most value. This value is reserved for flagging data that should be discarded. In the sampled beam, this course frequency channel is verified to be -32768-32768j (reserved value) and all other course channels, 0. In order to sample the beam data, the software requests the LMC data type “beam data”, and captures this using the DAQ receiver.

NOTE: This test only operates on the first TPM in a station.

NOTE: For data acquisition to function correctly, the network interfaces on the TPM must be working, as well as the link to the LMC destination. The LMC 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. All calibration coefficients are reset to a gain of 1 and all pointed delays are reset to 0

  3. Starting at the first polarisation of the first course frequency channel, a data pattern is generated which should trigger this polarisation to be flagged.

  4. A channelized data test pattern generator is started with the calculated pattern at the input to the tile beamformer in the firmware.

  5. An LMC snapshot of beam data is requested from the TPM

  6. Each course channel and polarisation in the captured beam is checked against an expected value. The channel and polarisation which should be flagged is verified, the rest are verified as 0.

  7. Returning to step 3, this is repeated for both polarisations in the first four course frequency channels.