01 02 03 04 05 06 07
0 1 1 1 1 1 0
08 09
0 1
10 11
1 0
12 13
1 0
14 15
0 1
16 17
0
18 19
0 0
20 21
1 0
BIT No.
DATA
NOTE: Check bits 22-31 and Parity bit 32 are not shown.
0
RPR 550IS Series
Page 3A - 4 TM1188 Issue 1
Figure 3: Syncword (Batch Position 0)
Codeword Structure
12. Each codeword has 32 bits, comprising:
a) Bits 1 to 21 Information Bits.
b) Bits 22 to 31 Error check bits following the Bose-Chaudhuri-Hocquenhen
(BCH) method.
c) Bit 32 Parity Bit. Gives an even bit parity check of the whole
codeword.
13. Codewords are transmitted with the first bit (Bit 1) as the most significant. Every
codeword must include at least one logic-state transition.
Types of Codeword
14. Types of Codeword available for use in Mk7 code format are as follows:
a) Synchronisation (Syncword)
b) System/Time
c) Date or In-Range
d) Address
e) Message
f) Idle (Idleword)
FIXED POSITION CODEWORDS
Syncword
15. The Syncword is the first codeword in a batch (Position 0). Its structure is shown in
Figure 3.
To Next Page
Loading...
