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14. RS232 INTERFACE
WTC retail scales can be optionally equipped in an RS232 interface allowing
transmission from the scale to an external device. Transmission parameters:
1200.7.N.1. (baud rate 1200, 7 bits of data, no parity, 1 stop bit). There is
continuous transmission set without possibility to change it.
Frame format:
02h
status
byte A
status
byte B
status
byte C
weight
display
6-digits
Tare
6-digits
Unit price
display
6-digits
To-pay value
display
6-digits
0Dh
Status byte A
Unit and work mode– always 2Dh in retail scales.
Status byte B
Scale status and point position:
More significant nibble – always 3.
Status
value
D3 Equilibrium
0 - stabilisation
1 – no stabilisation
D2 Overweight
0 – weighing
1 – overweight
D1 Indication
sign N/A
D0 tare
0 – no tare
1 – tare set
Status byte C
Reserved, always 20h (space).
Indications from displays are sent in a format of 6 digits, justified to the right,
with leading zeros.
