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Unformatted text preview: ts the status of frame
acceptance to the Frame Operation Procedure (FOP) at the sending end of the Transfer layer.
The controlling specification for how the CLCW is used within the COP is contained
in Reference .
The CLCW is the only reporting mechanism for the TC Transfer layer. Although it is not
necessary that the Telemetry reporting rate match the Telecommand transfer rate, some
minimum CLCW sampling rate is necessary for the proper operation of the COP.
The format of the CLCW is shown in Figure 4-3. CCSDS 202.0-B-2 Page 4-9 CCSDS HISTORICAL DOCUMENT November 1992 CCSDS HISTORICAL DOCUMENT
CCSDS RECOMMENDATION FOR TELECOMMAND: DATA ROUTING SERVICE CONTROL
IDENTIFICATION SPARE 1 2 3 2 6 2 (ALWAYS "0" FOR CLCW) FLAGS
LOCK LOCKOUT WAIT 1 1 1 FARM B
RETRANSMIT COUNTER 1 1 2 SPARE REPORT
VALUE 1 8 Figure 4-3: Command Link Control Word Format
The CLCW contains the following fields:
Field Length (Bits) CONTROL WORD TYPE
COP IN EFFECT
VIRTUAL CHANNEL ID
- No rf available
- No bit lock
FARM B COUNTER
REPORT VALUE CCSDS 202.0-B-2 1
32 bits (4 octets) Page 4-10 CCSDS HISTORICAL DOCUMENT November 1992 CCSDS HISTORICAL DOCUMENT
CCSDS RECOMMENDATION FOR TELECOMMAND: DATA ROUTING SERVICE Unless otherwise stated, all fields are required elements.
(1) CONTROL WORD TYPE (Bit 0)
This one-bit field shall be set to zero to indicate that the Operational Control Field
contains a CLCW. (2) CLCW VERSION NUMBER (Bits 1,2)
The two-bit CLCW VERSION NUMBER field is included to provide future growth
flexibility. However, at present a single “Version-1” CLCW format is defined in
this Recommendation. It shall be indicated by setting Bits 1,2 to value “00”. The
format of the Version-1 CLCW report is described herein. (3) STATUS FIELD (Bits 3,4,5)
Application of this field is mission-specified. It may...
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This document was uploaded on 03/06/2014.
- Spring '14