Source code for katgpucbf.spead

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# Copyright (c) 2020-2024, National Research Foundation (SARAO)
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# Licensed under the BSD 3-Clause License (the "License"); you may not use
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#   https://opensource.org/licenses/BSD-3-Clause
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"""Common SPEAD-related constants and helper function."""

from typing import Any

import numpy as np
import spead2

#: SPEAD ID of ``digitiser_id`` item
DIGITISER_ID_ID = 0x3101
#: SPEAD ID of ``digitiser_status`` item
DIGITISER_STATUS_ID = 0x3102
#: SPEAD ID of ``feng_id`` item
FENG_ID_ID = 0x4101
#: SPEAD ID of ``feng_raw`` item
FENG_RAW_ID = 0x4300
#: SPEAD ID of ``frequency`` item (which is actually a channel number).
FREQUENCY_ID = 0x4103
#: SPEAD ID of ``adc_samples`` item (digitiser data)
ADC_SAMPLES_ID = 0x3300  # Digitiser data
#: SPEAD ID of ``xeng_raw`` item
XENG_RAW_ID = 0x1800
#: SPEAD ID of ``timestamp`` item (number of ADC samples since the sync epoch)
TIMESTAMP_ID = 0x1600
#: SPEAD ID of ``bf_raw`` item
BF_RAW_ID = 0x5000
#: SPEAD ID of ``beam_ants`` item
BEAM_ANTS_ID = 0x5004
#: Maximum packet size to send (only used for descriptors)
MAX_PACKET_SIZE = 8872

#: Bit position in digitiser_status SPEAD item for ADC saturation flag
DIGITISER_STATUS_SATURATION_FLAG_BIT = 1
#: First bit position in digitiser status SPEAD item for ADC saturation count
DIGITISER_STATUS_SATURATION_COUNT_SHIFT = 32

#: SPEAD flavour used for all send streams
FLAVOUR = spead2.Flavour(4, 64, 48, 0)

#: Default UDP port
DEFAULT_PORT = 7148

#: Format for immediate items
IMMEDIATE_FORMAT = [("u", FLAVOUR.heap_address_bits)]
#: dtype for items that need to be immediate yet passed by reference
IMMEDIATE_DTYPE = np.dtype(">u8")


[docs] def make_immediate(id: int, value: Any) -> spead2.Item: """Synthesize an immediate item. Parameters ---------- id The SPEAD identifier for the item value The value of the item """ return spead2.Item(id, "dummy_item", "", (), format=IMMEDIATE_FORMAT, value=value)