These tables along with the associated actions

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Unformatted text preview: eptions E29 E29 S6 Figure 5-2: FOP-1 State Transitions: Initialization Protocol CCSDS 232.1-B-2 Page 5-24 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 E9 E103 E11 S2 S3 E8 E10 E12-B E6 E2 E2 E6 E11 E8 E9 E10 E32 E33 S1 Exceptions E29 Exceptions E29 E1 E1 E23 E31 Exceptions E29 S4 S5 E27 E24 E25 E34 Exceptions E29 Exceptions E29 S6 Figure 5-3: FOP-1 State Transitions CCSDS 232.1-B-2 Page 5-25 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 6 FARM-1 6.1 FARM-1 VARIABLES 6.1.1 GENERAL This section describes the variables used by the Frame Acceptance and Reporting Mechanism (FARM)-1 state machine. The complete meaning of these variables can only be fully understood in conjunction with a careful reading of the FARM-1 State Tables (table 6-1). These tables, along with the associated actions defined in 6.2, contain the master definition of FARM-1. The variables defined in this section are part of the definition of FARM-1. Any implementation of FARM-1 is likely to have in addition private, implementation-dependent variables. FARM-1 maintains the following variables for each Virtual Channel: a) State; b) Lockout_Flag; c) Wait_Flag; d) Retransmit_Flag; e) Receiver_Frame_Sequence_Number (usually referred to as ‘V(R)’); f) FARM-B_Counter; g) FARM_Sliding_Window_Width (also known as ‘W’); h) FARM_Positive_Window_Width (also known as ‘PW’); i) FARM_Negative_Window_Width (also known as ‘NW’). These variables are described in detail in subsections 6.1.2 through 6.1.8. 6.1.2 STATE The State of FARM-1 may be one of the following: a) Open (S1); b) Wait (S2); c) Lockout (S3). This variable represents the state of FARM-1 for the specific Virtual Channel. Each value of the State variable corresponds to a column in the FARM-1 State Table. CCSDS 232.1-B-2 Page 6-1 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 In ‘Open’ State, the state machine accepts in-sequence Transfer Frames and passes them to the Higher Procedures. In ‘Wait’ State, there is...
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This document was uploaded on 03/06/2014.

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