Gicam VIS100HE, Manual

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Serial communication
Continuous transmission protocol
The protocol is used for the continuous transmission.
The communication parameters are settable in DATA FORMAT (serial communication menu).
String transmitted at a frequency defined by the value set in the FILTER (Menu for setting the weighing pa-
rameters):
STX <state> <net> ETX <csum> EOT
<state> = character codified as per the following table (bit = 1if condition is TRUE)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 0 1 1
Tare in-
serted
Min.
weighing
Weight
stable
Zero
center
<net> = fields composed of 8 ASCII characters with the right value justified; characters can take values be-
tween "0" and "9" (30h and 39h), space (20h) or decimal point "." (2Eh); in case of negative weight the first
character of the field <weight> corresponds to "-".
In overweight conditions, the field takes on the value: "^^^^^^^^".
In underweight conditions, the field assumes the value: "_ _ _ _ _ _ _ _".
In weight reading error conditions, the field assumes the value: "O-L".
<csum> = check sum of the string data. It is calculated by executing the exclusive OR (XOR) of all characters
from STX (or from <Ind>) to ETX excluding the latter; the result of the XOR is broken down into 2 characters
considering the 4 upper bits (first character) and the lower 4 bits (second character) separately; the 2 charac-
ters obtained are then ASCII coded; (example: XOR = 5Dh; <csum> = "5Dh" ie 35h and 44h).
Manual transmission protocol
This protocol is used for the manual transmission to a PC; the instrument transmits the same string as in the
continuous transmission protocol (see above). The string is transmitted each time the key no 3 is pressed.
Transmission protocol on PC request (MASTER / SLAVE)
This protocol is used when the serial port COM1 is configured in the modality “transmission on request”. The
unit connected to the instrument (typically a personal computer) executes the MASTER function and is the
only unit that can initialize a communication procedure.
The communication procedure always has to be composed of the transmission of a string by the MASTER,
followed by an answer from the interested SLAVE
Communication parameters settable in DATA FORMAT (SERIAL COMMUNICATION MENU).
The master requests the weight with the string:
Ind N EOT
The SLAVE responds to each weight request from the MASTER with the string:
<Ind> N <state> <net> <tare> ETX <csum> EOT
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