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SERIAL COMMUNICATION PROTOCOLS
CONTINUOUS, AUTOMATIC AND MANUAL ASCII PROTOCOLS
The continuous transmission is carried out at the refresh rate of the weight, consistent with the serial
transmission baud rate. In case of communication on the ethernet port, the continuous transmission
frequency is limited to 12.5 Hz.
In case of FREE mode, the string is transmitted with Continuous, On Demand and Automatic protocols:
STX <status> <weight> ETX <chksum> EOT
In case of METRIC mode, the string is transmitted with On Demand and Automatic protocols:
STX <status> <weight> Weighing ID ETX <chksum> EOT
Where:
STX (start of text) = 0x02h
ETX (end of text) = 0x03h
EOT (end of transmission) = 0x04.
<status> = character encoded as per the following table (bit = 1 if condition TRUE):
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
1
1
Tare
Entered
Zero
band
Stable
weight
Centre
zero
<weight>
= field consisting of 8 ASCII characters with the weight value justified to the right (without
insignificant zeroes, with decimal points and negative signs).
The weight value transmitted may be the net weight, the gross weight or the peak value, depending on
the transmitted data selected (parameter MODE) in the configuration menu of the serial communication
ports (see related paragraph).
In conditions of overweight the field assumes the value: “^^^^^^^^”.
In conditions of underweight greater than 999999, the field assumes the value: “_ _ _ _ _ _ _ _”.
In conditions of weight reading error the field assumes the value: “ O-L ”.
<weighing ID>
= field consisting of seven ASCII characters with the identifier code of the weight justi-
fied to the right (without insignificant zeros).
<chksum>
= checksum of the string data. It is calculated by performing the exclusive OR (XOR) of all
the characters between STX (or from <Addr>) and ETX, with the exclusion of the latter two; the result
of the XOR is broken up into 2 characters considering the upper 4 bits (first character) and the lower
4 bits (second character) separately; the2 characters obtained are then ASCII encoded;
(example: XOR = 5Dh; <csum> = “5Dh” i.e. 35h and 44h).
In the case of automatic and manual communication protocols, between 2 successive transmissions
the weight must have a variation of at least 20 divisions.
Summary of Contents for DAT11
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