4
SERIAL INTERFACE PROTOCOL
When communicating in host mode using the Detecto AS-400D and AS-410D pounds/ounces
mode or AS-420D pounds only mode (not the UPS Pounds Mode), the serial data is
transmitted and received using 8 data bits, no parity and one stop bit. The host computer
sends request to the scale in the form of ASCII or HEX characters. The following is a list of
commands that can be sent by the computer and the scale response:
COMMAND
SCALE
RESPONSE
^N (control N, hex 0E)
Scale sends weight data continuously
^O (control O, hex 0F)
Stop continuous weight data
~ (tilde, hex 7E)
Weight data sent once in pounds/ounces mode
^X (control X, hex 18)
Zero the scale from the PC
ESCAPE (ESC, hex 1B)
Reset the scale from the PC
SCALE WEIGHT DATA STRINGS
AS-400D, AS-410D Pounds/Ounces Mode
Output Data Format:
SspppbLBbww.wbOZbxccE
where:
S
=
ASCII STX (HEX 02)
s
=
weight sign (space or -)
ppp
=
weight lb, leading zero suppressed
b = space
LB
=
the text "LB"
ww.w =
weigh ounces, leading zero suppressed
OZ
=
the text "OZ"
x
=
status: M = motion on scale
C = scale over capacity
cc
=
checksum - these two characters are the ASCII representation
of the computed checksum (HEX 3x, HEX 3x where xx is the
exclusive-or of all data from the STX to the status character)
E
=
ASCII ETX (HEX 03)
AS-420D Pounds ONLY Mode
Output Data Format:
swwwww.wxccE
(12 bytes total)
where:
s
=
weight sign (space or “-”)
wwwww.w
=
weight (lb and 1/10 lb including decimal point)
x
=
status: M = motion on scale
C = scale is over capacity
cc
=
checksum (ASCII representation of computed checksum)
E
=
ASCII ETX (03H)
