Ideas in Measuring ..
TECHNIQUES LIMITED
Page 24
LDU 68 Series Manual
The ST command is issued without any parameters and will return either the OK or ERR response.
If the ST command is accepted, the LDU responds with OK and the”zero action performed” bit of
the device status (IS) response will be active (1).
The RT command is issued without any parameters and will return either the OK or ERR response.
If the RT command is accepted, the LDU will respond with OK and the “tare active” bit of the
Device Status (IS) response will be set to 0
This command will activate the net weighing function by storing the current weight value as a tare.
The weight signal must be “stable” within the limits set by the no motion range (NR) and the no
motion time (NT) for the set tare command to be accepted and the “signal stable” bit of the device
status response (IS) to be active. (1)
ST Set Tare
This command cancels the tare and returns the weighing into gross mode.
RT Reset tare
Master (PC / PLC) sends
LDU XX.X responds
Result
ST
OK
New tare set
Master (PC / PLC) sends
LDU XX.X responds
Result
RT
OK
Tare deactivated
Issue 1h
Ideas in Measuring ..
TECHNIQUES LIMITED
Page 25
LDU 68 Series Manual
The following commands “Get” the Gross, Net, Tare, ADC sample, filtered, ‘Long’ weight and
Average values from the LDU.
5.7 Output commands GG, GN, GT, GS, GF, GW, GA
This command gets the gross weight value.
GG Get Gross weight value
Master (PC / PLC) sends
LDU XX.X responds
Result
GG
G+01.100
Gross weight value = 1.100 divisions
This command gets the net weight value.
GN Get Net weight value
Master (PC / PLC) sends
LDU XX.X responds
Result
GN
N+01.000
Net weight value = 1.000 divisions
This command gets the tare weight value.
GT Get Tare value
Master (PC / PLC) sends
LDU XX.X responds
Result
GT
T+0.100
Tare value = 0.100 divisions
This command gets the actual Analogue to Digital Converter (ADC) value. This can be useful
during development or when calibrating to see how much of the ADC range is being used.
For service applications it may be helpful to note the value of ADC at no load and full load.
GS Get ADC sample value
Master (PC / PLC) sends
LDU XX.X responds
Result
GS
S+125785
ADC value = 125785 counts
GF Get the Filtered value (Display Mode ONLY)
Master (PC / PLC) sends
LDU XX.X responds
Result
GF
F+01.000
Filtered weight value = 1.000 divisions
This command gets the filtered weight value. The filtered weight value is a rolling average of the
weight readings over a time set by the FF command. This command is normally used when the
LDU is connected to an external display where a more stable result is required.
GW Get the ‘Long’ weight value
This command gets the ‘long’ weight value. The GW command is issued without any parameters
and the response is a single string in the format
W+00100+011005109
which contains the current
net weight, the current gross weight, the status values and a checksum. The first two sections of
the returned string contains the net weight and the gross weight values followed by two
hexadecimal characters which represent two bitmapped status indicators. The last two
hexadecimal characters represent the checksum, which is the inverse of the sum of all the ASCII
values of the string plus 1, not including the checksum characters.
Issue 1h
