Diatron MI PLC
rev 1.09
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10.2. Serial Communication Protocol
This document describes protocols 1.0, 1.7, 2.20, 2.23 and 3.0.
Only protocol version 3.0 contains sending Limits for parameters.
10.2.1.General Description
software is able to make serial connection link to a receiver device (computer) by
connecting to the serial port of the instrument. If Serial Communication Speed (Utilities /
Settings / Customize / General Settings) Baud Rate setting is set to a valid value (other than
“Offline”), will try to initiate a communication sequence.
initiates serial communication, the receiver must respond to this request.
The hardware protocol is:
8 data bit, 1 stop bit, no parit
y. If the other side is not
responding within 1 second, will repeat the transmission twice, but if still no
response, the other side will be supposed to be not ready to receive data, and thus
will not try to communicate any more.
From this state it can wake up by receiving an <ENQ> (ASCII code 5) character from the
other side, and will immediately respond with an <ACK> (ASCII code 6). From this
point will send data if it is ready for transmission.
The communication is based on packages.
There are 7 package types
:
INIT package: Device identification, software version, current date and time.
DATA package: Sample and patient information, measured parameters, and markers.
RBC package: Sample information, RBC histogram.
WBC package: Sample information, WBC histogram.
PLT package: Sample information, PLT histogram.
XML file with FULL record structure information
FULL record transmission
The communication sequence is always started with an INIT package. If the link is
successful, will send DATA package, and the receiver can request RBC, WBC and
PLT packages at acknowledge.
If serial communication protocol is set to version 3.0, will send XML and FULL
packages.
Special characters used in the communication
:
Character
ASCII code
<SOH>
1
<STX>
2
<ETX>
3
<EOT>
4
<ENQ>
5
<ACK>
6
<HT>
9
<LF>
10
<NAK>
21
<SPACE>
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