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Application Note

Using ASTi's Tactical Data Link/Data Bridge Feature (#26.2)

Part II (DACS Model Builder & Telestra 2)

DIS Signal PDU Format

NOTE: The DIS PDU convention is to use Big Endian format.

The DIS Signal PDU is structured as follows:

PDU Header 96 bits
Transmitter Entity ID 48 bits
Radio ID 16 bits
Encoding Scheme 16 bits
Data Link Message Type 16 bits
Sample Rate 32 bits
Length 16 bits
Samples 16 bits
Data #1 8 bits
...
Data #n 8 bits

The above fields are structured as follows:

PDU Header

Description Type Required Value
Protocol Version 8 bit unsigned integer 4, 5, or 6
Exercise ID 8 bit unsigned integer Current DIS exercise number
PDU Type 8 bit enumeration 26 decimal
PDU Family 8 bit unsigned integer 4
Time Stamp 32 bit unsigned integer
PDU Length 16 bit unsigned integer Signal PDU size in bytes
Padding 16 bit unsigned integer

Transmitter Entity ID

Description Type Required Value
Site 16 bit unsigned integer Site number of DIS machine used to transmit data
Application/Host 16 bit unsigned integer Application/Host number of DIS machine used to transmit data
Entity 16 bit unsigned integer Entity number of radio transmitting data

Radio ID

Description Type Required Value
Radio ID 16 bit unsigned integer Radio ID of radio transmitting data

Encoding Scheme

Description Type Required Value
Encoding Scheme 16 bit enumeration See DIS standard. First two bits identifies data class (00=voice). DACS and Telestra application software uses non-zero numbers to identify non-voice data per DIS standard.

Data Link Message Type

Description Type Required Value
Data Link Msg Type 16 bit enumeration See DIS standard. Not used by the DACS or Telestra application software.

Sample Rate

Description Type Required Value
Sample Rate 32 bit unsigned integer See DIS standard. For Telestra this field is used as the band rate in bits/second. Not used by the DACS application software.

Length

Description Type Required Value
Length 16 bit unsigned integer See DIS standard. Data length in bits. For Telestra this field is used for the data bandwidth considerations. Not used by the DACS application software.

Samples

Description Type Required Value
Samples 16 bit unsigned integer See DIS standard. Not used by the DACS or Telestra application software.

Data #1 through #n

Description Type Required Value
Data 8 bit unsigned integer See DIS standard. Application specific data. Not used by DACS application software.