An array of PacketFields?

[joeymukherjee]

How would I do something like this? I have a fixed length packet, but within the packet, I have an array of other packet fields. I made some pseudocode below which defines a SENSOR_GRID which have 5 packet fields that repeat 48 times.

THIS IS NOT VALID CODE:. (so no cut/paste!)

pkt = ccsdspy.FixedLength([
     PacketField(name='SHCOARSE', data_type='uint', bit_length=32),
     PacketField(name='SHFINE',   data_type='uint', bit_length=20),
     PacketField(name='OPMODE',   data_type='uint', bit_length=3),
     PacketField(name='SPACER',   data_type='fill', bit_length=1),
     PacketField(name='VOLTAGE',  data_type='int',  bit_length=8),
     PacketArray(
         name='SENSOR_GRID',
         contents=[
             PacketField(name='ID', data_type='uint', bit_length=32),
             PacketField(name='FLAGS',   data_type='uint', bit_length=8),
             PacketField(name='COUNTER',   data_type='uint', bit_length=3),
             PacketField(name='DATA',   data_type='uint', bit_length=192),
             PacketField(name='CHECKSUM',  data_type='int',  bit_length=8)
         ],
         repeat=48
     ),
])

[ddasilva]

Hi @joeymukherjee,

Thanks for writing! I think the way to do this is as follows.... right now there isn't something like what you're proposing, but this solution should get you going!

packet_fields = [
     PacketField(name='SHCOARSE', data_type='uint', bit_length=32),
     PacketField(name='SHFINE',   data_type='uint', bit_length=20),
     PacketField(name='OPMODE',   data_type='uint', bit_length=3),
     PacketField(name='SPACER',   data_type='fill', bit_length=1),
     PacketField(name='VOLTAGE',  data_type='int',  bit_length=8),
]

for i in range(48):
    packet_fields.extend([
             PacketField(name=f'ID{i}', data_type='uint', bit_length=32),
             PacketField(name=f'FLAGS{i}',   data_type='uint', bit_length=8),
             PacketField(name=f'COUNTER{i}',   data_type='uint', bit_length=3),
             PacketField(name=f'DATA{i}',   data_type='uint', bit_length=192),
             PacketField(name=f'CHECKSUM{i}',  data_type='int',  bit_length=8)
     ])

pkt = ccsdspy.FixedLength(packet_fields)