SYSMEX KX-21 - Page 297

TECHNICAL INFORMATION
Sysmex KX-21 Operator’s Manual -- Revised October 1998 B-3
1.2 Software
1. Communication Format
1) Code
ASCII codes are used for output.
(Except for K-DPS output)
2) Structure of text
"STX" (02 H) is sent prior to data and "ETX" (03 H) is sent at the end of data.
(Except for K-DPS output)
S
T
X
E
T
X
Order of transmission
Figure B-1-3: Order of Transmission
3) Communication protocol
The following 2 protocols are provided in the system, and can be selected according to
the system status.
• Class A
One-way transmission to the host computer without requiring ACK nor NAK from
host computer.
• Class B
The KX-21 transmits data and then waits for ACK or NAK to complete the data
transmission.
Analysis data is sent.
Analysis data transmission
is completed correctly.
Communication error
occurs.
Analysis data is sent
automatically (retrying up
to 3 times). If the reply is
still NAK after 3 retries,
instruction is made whether
the same data is sent again
or the transmission is
canceled by key input.
Analysis data is received.
When an error does not
occur, ACK (06H) is sent.
When an error occurs, NAK
(15H) is sent.
KX-21 Host computer
ACK
NAK
Figure B-1-4: Data Transmission