DirecTV DTV-MD0-0058 - Manual (Page 15)

DIRECTV Set-top box information for the installer
DIRECTV Proprietary November 17, 2005
Version 1.1.a Page 15 of 49 DTV-MD-0058
Start
Reset Command
Parser
(Parser is free)
*Command
Prefix (0xFA)?
Send
STB Response
= NACK_PREFIX
NO
**Command Parser
attaches to current
data port
(Parser is in use)
*Known
Command?
Send
STB Response
= NACK_CMD
YES
NO
*2 Byte
Command?
Read 2 nd Byte of a 2
Byte Command
*Known
Command?
Send
STB Response
= ACK_CMD
YES
NO
YES
YES
NO
A
A
Send
STB Response
= ACK_RESET
Send
STB Response
= DATA_ERROR
Send
STB Response
= CMDBUF_OVFL
Input
Parameters?
*Correct # of
Input
Parameters?
Send
STB Response
= NACK_PARAMS
Send
STB Response
= ACK_PARAMS
Execute Command
and send Return
Data Stream as
appropriate
(Parser is Busy)
Command
completed
successfully ?
Send
STB Response
= NACK_FCNOK
Send
STB Response
= ACK_FCNOK
(Parser is not busy)
YES
YES
NO
NO
YES
NO
Figure 4. Service Command Parser Flowchart