098-00564-000 Revision A3 – July, 2013
TimeProvider 2300/2700 User’s Guide
303
Appendix B Specifications and Factory Defaults
Specifications
Figure B-2. TOD China Mobile Frame Structure
Table B-16. TOD China Mobile Frame Details
Field Name
Field Length
Description
Sync Char 1
1 byte
Part of Frame Header
0x43 = ASCII character “C”
Sync Char 2
1 byte
Part of Frame Header
0x4D = ASCII character “M”
Class
1 byte
Basic classification of TOD China Mobile
message
ID
1 byte
Serial number of TOD China Mobile message
Length
2 bytes
Length of payload only
(Does
not
include Frame Header, Message Header,
Length Field itself, or FCS)
Payload
16 bytes
Contains the message content
See
, and
for Time Message details.
Frame Check
Sequence
(FCS)
1 byte
Generating polynomial FCS is:
G(x) =
x
8
+
x
5
+
x
4
+1
Initial value of FCS is set to 0xFF, and there is
no need to negate the input data. Checksum
calculation uses right-shift calculation, and
there is no need to negate the output frame
check data. When the frame check sequence
is transmitted, the LSB (bit 0) is transmitted
first.