APPENDIX C. BINARY TELECOMMUNICATIONS

Representing the bits in the first byte of each two byte pair as ABCD EFGH (A is the most significant bit, MSB), the byte pairs are described here.

LO RESOLUTION FORMAT - D,E,F,NOT ALL ONES
Bits

Description

A

Polarity, 0 = +, 1 = -.

B, C

Decimal locators as defined below.

D-H plus

13 bit binary value (D=MSB).

second

Largest possible number without D,

 

E, and F all 1 is 7167,

byte

but CSI defines the largest

 

allowable range as 6999.

The decimal locators can be viewed as a negative base 10 exponent with decimal locations as follows:

B

C

Decimal Location

0

0

XXXX.

0

1

XXX.X

1

0

XX.XX

1

1

X.XXX

DATA TYPE WHEN D,E,F, ALL EQUAL ONE

If D, E, and F are all ones, the data type is determined by the other bits as shown below. X implies a "don't care" condition; i.e., the bit can be either 1 or 0 and is not used in the decode decision.

A

B

C

D

E

F

G

H

DATA TYPE AND SECOND BYTE FORMAT

1

1

1

1

1

1

X

X

A,B,C, = 1 - Start of Output Array, G & H are the most

 

 

 

 

 

 

 

 

significant bits of the Output Array ID. All 8 bits of the

 

 

 

 

 

 

 

 

2nd byte are also included in the ID.

X

X

0

1

1

1

X

X

C = 0 - First byte of a 4 byte value.

0

0

1

1

1

1

X

X

A,B = 0; C = 1 - Third byte of a 4 byte value.

0

1

1

1

1

1

1

1

A = 0; remaining bits = 1 - First byte of a 2 byte

 

 

 

 

 

 

 

 

"dummy" word. The CR10 always transmits a 0 for the

 

 

 

 

 

 

 

 

2nd byte, but the word can be decoded on the basis of

 

 

 

 

 

 

 

 

the 1st byte only.

HI RESOLUTION FORMAT

Continuing to use the A-H bit representation, the four byte number is shown below as two two byte pairs.

 

AB0111GH

XXXXXXXX 001111GH

XXXXXXXX

 

 

 

 

BITS, 1ST BYTE,

 

 

 

1ST PAIR

DESCRIPTION

 

 

CDEF = 0111

Code designating 1st byte pair of four byte number.

B

Polarity , 0 = +, 1 = -.

 

G,H,A,

Decimal locator as defined below.

 

2nd byte

16th - 9th bit (left to right) of 17 bit binary value.

 

ABCDEF = 001111

Code designating 2nd byte pair of four byte number.

G

Unused bit.

 

 

H

17th and MSB of 17 bit binary value.

 

2nd byte

8th - 1st bit (left to right) of 17 bit binary value.

 

C-4