Document number
205065
Version
Rev. N
Issue date
2019-02-04
Sirius OBC and TCM User Manual
Page
162
of
174
, where XXXXXXXX is the value the FARM shall set the Receiver Frame Sequence Number,
V(R).
10.6.4. Frame Error Control Field
The Frame Error Control holding an error detection code (checksum) shall always be
included in the telecommand transfer frames, which allows the receiving application to verify
the integrity of the telecommand frame data.
The checksum shall be calculated using CRC with polynomial 0x8408, LSB first, and initial
value 0xFFFF over the whole TC Transfer Frame except the two last octets.
10.6.5. Telecommand Packet
All Telecommand Packets in Frame Data Units shall conform to the format in Figure 10.4
below.
Figure 10.4 Telecommand Packet
Table 10-3 Packet Header
Field
Description
Comment
Version number
Packet structure version number.
Shall be set to 0
Type
Distinguishes telecommand
packets and telemetry packets.
For telecommands, the type shall
be set to 1
Data Field Header Flag
With exceptions of CPDU
telecommands, all telecommand
packets shall have a data field
header so this bit shall be set to
1
Application Process ID
Sets the destination on-board
application for the telecommand
packet.
Sequence Flags
The TCM-S does only support
stand-alone packets, so this field
shall be set to ‘11’