Page B-7
B.1.8 DETECTO DEMAND / CONTINUOUS FORMAT
The Detecto SDF (Serial Data Format) can work both as a Demand type and a Continuous
type, depending on the commands received from the host. Upon power up, the scale
defaults to Demand type. The scale disregards the type setting programmed for Mode of
Serial Transmission.
Figure B-11 shows the weigh data / status record sent to the host when the scale receives a
Print (“~”) command. The same weigh data record is sent out of the serial port if the PRINT
key is pressed on the scale’s front panel. The output records are identical when operating as
a Demand type or a Continuous type.
NOTE:
Since this SDF (Serial Data Format) does not support units of measure. It is
recommended that lb/kg conversion be disabled.
<STX>
<POL> XXX
LB
<SB>
Polarity:
<SP> = Positive
– = Negative
Weight digits*
Start
Transmission
<SP>
<SP>
Space
Space
* with leading zero suppression
<ETX>
End
Transmission
XX.X
Weight digits*
OZ
<SP>
Status Byte:
M = Motion
C = Over
<CHK1> <CHK2>
Space
Checksum Byte 1
Checksum Byte 2
FIGURE B-11. Detecto Weigh Data / Status Record
B.1.8.1 RECOGNIZED HOST COMMANDS
These commands are issued from the host to the scale and are single ASCII
characters.
“~”
- This command is sent to the scale to print the indicated display. The host
should check the status bytes to determine if the scale is in motion, positive
overload or negative overload.
“<SO>”
- This command is sent to the scale to change the scale to Continuous
type. Even if successful, the host receives no response from the scale.
“<SI>”
- This command is sent to the scale to change the scale to Demand type.
Even if successful, the host receives no response from the scale.
NOTE
: You can execute the <SO> and <SI> host commands by hitting Ctrl-N for
<SO> and Ctrl-O for <SI> on your computer’s keyboard.
