This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ved value of the FARM’s NEXT EXPECTED FRAME
SEQUENCE NUMBER V(R). The FARM V(R) counter shall increment once each
time a Type-AD TC Frame is accepted on a particular Virtual Channel.
The precise specifications for use of the REPORT VALUE are contained in
Reference . Necessarily, separate counters shall be maintained for each Virtual
4.3 STANDARD PROCEDURES WITHIN THE LAYER Standard procedures within the Transfer layer are concerned with the following operations:
(1) (2) At the receiving end of the system, performing standard “Frame Validation
Checks” on all TC Frames reconstituted from the Coding layer. (3) 4.3.1 At the receiving end of the system, reconstituting TC Frames from the data stream
provided by the Channel Service Coding layer and removing any Fill Data
transferred from that layer. At both ends of the system, executing the Command Operation Procedure which
is used to move TC Frames across the Transfer layer, including performing frame
acceptance checks and establishing and using various counters, numbers and
windows. FRAME DELIMITING AND FILL REMOVAL PROCEDURE The Telecommand Channel Service (Reference ) resides immediately below the Transfer
layer. At the sending end of the TC System, the Transfer layer passes one or more TC
Frames to the Channel Service Coding layer, which encodes the frames to protect them from
errors which may be introduced as they are transmitted through the physical channel. Fill
Data may have to be inserted by the Channel Service to ensure correct transmission of all
The receiving end of the Transfer layer receives as an input from the Coding layer a series of
data octets, corresponding to the decoded frame(s), which have been declared “clean” by the
Coding layer insofar as they contain no detected errors. The Coding layer provides a “Data
Start” signal to the Transfer layer, indicating that data are being transferred.
The Data Start signal shall be set TRUE while the Coding layer is in the process of actively
View Full Document
This document was uploaded on 03/06/2014.
- Spring '14