Document number
205065
Version
Rev. N
Issue date
2019-02-04
Sirius OBC and TCM User Manual
Page
161
of
174
Virtual Channel ID
Virtual channel ID of
Telecommand
Only virtual channel 0 is
supported for TCs to be
handled by the SW in TCM-
S.
Virtual channel 2 is
supported for CPDUs
FRAME LENGTH
Shall be set to total number of
octets in the TC Transfer Frame -
1
The maximum number of
octets in the TC Transfer
Frame is 1024.
FRAME SEQUENCE
NUMBER
The number of the TC Transfer
Frame
The Frame sequence
number enables the FARM
to check sequence of
incoming Type-A transfer
frames
10.6.3. Transfer Frame Data Field
TC Transfer Frames send to the TCM-S is expected to contain the Frame Error Control
Field, which results in a maximum length of 1017 octets of the Transfer Frame Data Field.
The Transfer Frame Data Field shall contain either a Frame Data Unit (for Type-D Transfer
Frame) or a control command (for Type-C Transfer Frames).
For Transfer Frames carrying a Frame Data Unit, a Segment Header follows the Transfer
Frame Primary Header, see Figure 10.3. For Frame Data Units, the user data shall contain a
complete packet, see 10.6.5
Figure 10.3 Segment Header
Table 10-2 Segment Header
Field
Description
Comment
SEQUENCE FLAGS
Shall be set to ‘11’ since no
segmentation is supported on
TCM-S
MAP ID
Shall be set to 0.
Only MAP ID 0 is supported
on TCM-S
Two control commands are supported by TCM-S: Unlock and Set V(R). The Unlock Control
Command consists of a single octet containing “all zeroes”. The Set V(R) Control Command
shall consists of three octets with the following values:
10000010 00000000 XXXXXXXX