DIS Data Dictionary - PDU Data

Current standard: IEEE 1278.1

Comment PDU

Size: 320
Description: Arbitrary messages (character strings for example) shall be entered into the data stream by using a Comment PDU. The Comment PDU shall consist of the following fields:

a) Simulation Management PDU Header - These fields shall identify the PDU header information, the originating entity, and the intended receiving entity. The Simulation Management PDU Header shall be represented by the Simulation Management PDU Header Record described in 5.3.29.
b) Number of Fixed Datum Fields - This field shall specify the number of fixed datum fields required to supply database names or character fields which are less than 32 bits. This field shall be represented by a 32-bit unsigned Integer.
c) Number of Variable Datum Fields - This field shall specify the number of variable datum fields required to supply database names or character fields which exceed 32 bits. This field shall be represented by a 32-bit unsigned iteger.
d) Variable Datum Values - These fields shall specify the types of Variable Datum, their length and their value. This field shall be represented by a Variable Datum Record (see 5.3.32).

The maximum number of Fixed and Variable Datum Records in a Comment PDU is a function of the maximum PDU size specified in the Standard for Interactive Simulation - Communication Services and Profiles, and must adhere to the following relationship



The Comment PDU is represented in Table 53.

PDU Components:

Item Name	Bit Length	Opt	Opt Ctl	Rpt	Rpt Ctl
PDU Header Record	96
Originating Entity ID Record	48
Receiving Entity ID Record	48
Number of Fixed Datum Records Field	32
Number of Variable Datum Records Field	32
Variable Datum Record Record	64	Yes	Number of Variable Datum Records	Yes	Number of Variable Datum Records