Pavone Systems MCT 1302, Техническое руководство, Страница: 66 / 84

Page 64
SERIAL COMMUNICATION PROTOCOLS
CONTINUOUS ASCII PROTOCOL
The continuous sending is performed at the weight update frequency, compatibly with the serial
transmission baud rate. In case of communication on the Ethernet port, the frequency of the continuous
transmission is limited to 12.5 Hz.
STX <status> <weight> ETX <chksum> EOT
where:
STX (start of text) = 0x02h
ETX (end of text) = 0x03h
EOT (end of transmission) = 0x04.
<status> = character coded as in the following table (bit = 1 if condition is 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
Zero
center
<weight> = field consisting of 8 ASCII characters with the weight value justified on the right without
non-significant zeros, with any decimal point and negative sign.
The sent weight value can be the net weight, the gross weight or the peak value, based on the selec-
tion of the sent data (MODE parameter) in the setup menu of the serial communication ports (see the
relevant paragraph).
In overweight conditions, the field assumes the value: “^^^^^^^^”.
In conditions of weight greater than 99999, the field assumes the value: “_ _ _ _ _ _ _ _”.
In conditions of wrong reading, the field assumes the value: “ O-L ”.
<cheksum> = sum of control of string data. It is calculated by executing the exclusive OR (XOR) of all the
characters from STX (or from <Addr>) to ETX excluding the latter; the result of the XOR is decomposed
into 2 characters considering separately the 4 upper bits (first character) and the lower 4 bits (second
character); the 2 characters obtained are then ASCII coded;
(example: XOR = 5Dh; <csum> = “5Dh”, namely 35h and 44h).