8.2.5.1. Custom Data Field

Note

Use await port.payload_mode.set_cdf() to set the port’s payload mode to Custom Data Field.

8.2.5.1.1. Field Offset

This command is part of the Custom Data Field (CDF) feature. The CDF offset for the stream is the location in the stream data packets where the various CDF data will be inserted. All fields for a given stream uses the same offset value. The default value is zero (0) which means that the CDF data will be inserted at the very start of the packet, thus overwriting the packet protocol headers. If you want the CDF data to start immediately after the end of the packet protocol headers you will have to set the CDF field offset manually. The feature requires that the P_PAYLOADMODE command on the parent port has been set to CDF. This enables the feature for all streams on this port.

Corresponding low-level API class: PS_CDFOFFSET

# Custom Data Field
# Use await port.payload_mode.set_cdf() to set the port's payload mode to Custom Data Field.

# Field Offset
await stream.cdf.offset.set(offset=1)

resp = await stream.cdf.offset.get()
resp.offset

8.2.5.1.2. Byte Count

This command is part of the Custom Data Field (CDF) feature. It controls the number of custom data fields available for each stream. You can set a different number of fields for each stream. Changing the field count value to a larger value will leave all existing fields intact. Changing the field count value to a smaller value will remove all existing fields with an index larger than or equal to the new count. The feature requires that the P_PAYLOADMODE command on the parent port has been set to CDF. This enables the feature for all streams on this port.

Corresponding low-level API class: PS_CDFCOUNT

# Byte Count
await stream.cdf.count.set(cdf_count=1)

resp = await stream.cdf.count.get()
resp.cdf_count