625 ignore this action involves no processing by farm

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Unformatted text preview: (table 6-1). Some of the actions defined here are used in the definition of other actions. CCSDS 232.1-B-2 Page 6-6 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 NOTE – It should be noted that the COP-1 Frame Sequence Number is an 8-bit field. Therefore, all arithmetic in the FARM concerning the related fields V(R), N(S) PW and NW should be performed modulo 256. In particular, this should be taken into account when reading the event conditions contained in the FARM-1 State Tables. 6.2.2 ‘ACCEPT’ This action involves: a) placing the FDU contained by the Transfer Frame in a buffer; b) generating an ‘FDU Arrived Indication’ signal to the Higher Procedures. If a Type-BD FDU has been placed in a buffer erasing another unread FDU, an optional ‘Aborted Indication’ may be sent to the Higher Procedures. 6.2.3 ‘DISCARD’ This action involves: Discarding the received Transfer Frame. 6.2.4 ‘REPORT’ This action involves: Generating information to be placed in the CLCW based on the current status of FARM-1. 6.2.5 ‘IGNORE’ This action involves no processing by FARM-1. 6.3 6.3.1 FARM-1 STATE TABLE STATE MACHINE FARM-1 is defined as a state machine that is described in a State Table. The basic operation principle of the state machine is that it remains in a ‘State’ until an ‘Event’ occurs. When an Event occurs, it is analyzed until it is fully identified and then the Actions specified for the combination of that Event and that State are executed. Finally, the State variable is updated with the new State value specified for the combination. The FARM-1 state machine is described in the FARM-1 State Table in table 6-1. NOTE – A brief explanation on the format of the State Table is given in annex C. CCSDS 232.1-B-2 Page 6-7 September 2010 RECOMMENDED STANDARD FOR COMMUNICATIONS OPERATION PROCEDURE-1 6.3.2 NOTES TO FARM-1 STATE TABLE Transfer Frame Validation Not included in the FARM-1 State Table are operations concerning the validation of the Transfer Frame. The event ‘Valid Frame Arrives’ means that the Lower Procedures have pl...
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This document was uploaded on 03/06/2014.

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