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 |
Go to DIS standard. Uppermost two bits identifies data class (00=voice). DACS and Telestra application software uses nonzero numbers to identify nonvoice data per DIS standard. The DACS and Telestra discard voice data messages. |
Data Link Message Type
| Description |
Type |
Required Value |
| Data Link Msg Type |
16-bit enumeration |
Go to DIS standard. Not used by the DACS or Telestra application software. |
Sample Rate
| Description |
Type |
Required Value |
| Sample Rate |
32-bit unsigned integer |
Go to DIS standard. For Telestra, this field operates as the band rate in bits/second. Not used by the DACS application software. |
Length
| Description |
Type |
Required Value |
| Length |
16-bit unsigned integer |
Go to DIS standard. Data length in bits. For Telestra, this field is for data bandwidth considerations. Not used by the DACS application software. |
Samples
| Description |
Type |
Required Value |
| Samples |
16-bit unsigned integer |
Go to DIS standard. Not used by the DACS or Telestra application software. |
Data #1 through #n
| Description |
Type |
Required Value |
| Data |
8-bit unsigned integer |
Go to DIS standard. Application-specific data. Not used by DACS application software. |
