Hitachi 902 Service Manual page 400

(b) Transfer of absorbance data in entire reaction process (from analyzer to host)
1) Specification of size
The size of text is specifiable on the communication parameter screen.
Select either 256 or 512 bytes. On selection of 256 or 512 bytes, text is
transferred divided as shown below.
(i) When 256-byte mode is specified for text size
1B
First STX
Analytical data 4 BLANK1
1B 1B 2B
Final STX
(ii) When 512-byte mode is specified for text size
1B
Final STX
Analytical data 4 BLANK1
2) Transfer unit
This text is transferred in units of channel. Even when the text size is 256
bytes, transfer is completed in a single text if the point count is 24 or less.
The frame character at that time is not '1' but ':'.
3) Sample information
Refer to "sample information" in (2) of 16.6.2.
1B 2B
1 Fu Sample information
6B × 4
1B
ABS24 ETX
37B
: Fu Sample information
ABS35 ETX
1B 2B
: Fu Sample information
6B × 4
1B
ABS35 ETX
16 - 33
10B × 4
37B
Analytical data 1
3B
BLANK4 Point count
1B
BCC (Variable)
6B × point count
3B
Point count
BCC
10B × 4
37B
Analytical data 1
3B
BLANK4 Point count
1B
BCC (Variable)
6B × point count
ABS1
ABS25
6B × point count
ABS1