Astro

USLP Transfer Frame operations: encode, decode, inspect, and generate USLP Transfer Frames (CCSDS 732.1-B-3).

Subcommands

Command	Description
`astro usdl decode`	Decode a USLP Transfer Frame into header fields and data
`astro usdl encode`	Construct a USLP Transfer Frame from fields
`astro usdl inspect`	Annotated frame breakdown with hex dump
`astro usdl gen`	Generate synthetic USLP Transfer Frames

Common flags

Flag	Default	Description
`--input`	`hex`	Input format: `hex` or `bin`
`--format`	varies	Output format: `text`, `json`, or `hex`
`--no-fecf`	`false`	Frame carries no FECF (decode/inspect)
`--insert-len`	`0`	Octets of insert zone (decode/inspect)

astro usdl decode

Decode a USLP Transfer Frame from raw bytes. FECF is verified automatically.

astro usdl decode [file] [flags]

Flags

Flag	Default	Description
`--input`	`hex`	Input format: `hex` or `bin`
`--format`	`text`	Output format: `text`, `json`, or `hex`
`--no-fecf`	`false`	Frame carries no FECF
`--insert-len`	`0`	Octets of insert zone the frame carries

Examples

# Decode from hex stdin
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405 | astro usdl decode --input hex

# Decode with JSON output
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405 | astro usdl decode --input hex --format json

astro usdl encode

Construct a USLP Transfer Frame from header fields and data. FECF is computed automatically.

astro usdl encode [flags]

Flags

Flag	Default	Description
`--scid`	`0`	Spacecraft ID (0-65535)
`--vcid`	`0`	Virtual Channel ID (0-63)
`--mapid`	`0`	MAP ID (0-15)
`--data`	required	Data field as hex string
`--ocf`		Operational Control Field as hex string (4 bytes)
`--upid`	`0`	USLP protocol identifier (0-31)
`--rule`	`7`	TFDZ construction rule (0-7)
`--vcf-len`	`0`	VCF count field length in octets (0-7)
`--vcf-count`	`0`	VCF count value
`--format`	`hex`	Output format: `text`, `json`, or `hex`

Examples

# Encode a basic USLP frame
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405

# Encode with an OCF
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405 --ocf 00000000

# Encode with JSON output
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405 --format json

astro usdl inspect

Display an annotated breakdown of a USLP Transfer Frame showing all header fields, data regions, and hex dump.

astro usdl inspect [file] [flags]

Flags

Flag	Default	Description
`--input`	`hex`	Input format: `hex` or `bin`
`--no-fecf`	`false`	Frame carries no FECF
`--insert-len`	`0`	Octets of insert zone the frame carries

Examples

# Inspect from hex stdin
astro usdl encode --scid 100 --vcid 1 --mapid 0 --data 0102030405 | astro usdl inspect --input hex

# Inspect a binary file
astro usdl inspect --input bin frame.bin

astro usdl gen

Generate a stream of synthetic USLP Transfer Frames with incrementing sequence numbers and random data.

astro usdl gen [flags]

Flags

Flag	Default	Description
`--scid`	`0`	Spacecraft ID (0-65535)
`--vcid`	`0`	Virtual Channel ID (0-63)
`--mapid`	`0`	MAP ID (0-15)
`--count`	`10`	Number of frames to generate
`--data-size`	`64`	Data field size in bytes per frame
`--format`	`bin`	Output format: `bin` or `hex`

Examples

# Generate 10 USLP frames
astro usdl gen --scid 100 --vcid 1 --mapid 0 --count 10 --data-size 64

# Generate with hex output
astro usdl gen --scid 100 --vcid 1 --count 5 --data-size 32 --format hex

See also: the protocol page for the standard and the Go API, and the conformance statement for what is and is not implemented.