Ideas in Measuring ..
TECHNIQUES LIMITED
Page 20
LDU 68 Series Manual
ZT Zero tracking (continued)
This command restores the LDU back to the original factory settings. The data will be written back
into EEPROM and the TAC will be incremented by 1
Please note: All calibration and set up data will be lost if the FD command is issued !
FD Factory default settings
Master (PC / PLC) sends
LDU XX.X responds
Result
CE
E+00017 (example)
Current TAC value is 17
CE_17
OK
Calibration commands enabled
FD
OK
Factory default settings restored
This command stores the calibration values in EEPROM and causes the TAC code to be
incremented by 1.
If the CS command is not issued and the power to the LDU fails or is
turned off, all changes to the calibration values will be lost.
The CS command saves all calibration group values as set by CZ, CG, CM, DS, DP and ZT. To do
this issue the CE command with the current TAC code followed by CS.
CS Save the calibration values
Master (PC / PLC) sends
LDU XX.X responds
Result
CE
E+00017 (example)
Current TAC value is 17
CE_17
OK
Calibration commands enabled
CS
OK
Calibration values stored
Issue 1h
Zero tracking will only be performed on values within the zero track band, at a rate of 0.4 d per
second where d = display set size (see DS command). The zero will only be tracked if it is within
the zero track range. See ZR command. If ZT is set to 0, zero tracking is turned off. Factory
default: ZT = 0.
This command sets an initial zero range on power up in divisions. If ZI is set to 0 (default value) an
initial zero on power up is not performed. If ZI is set to something other than zero, the device will
automatically perform a set zero on power up provided that the weight value is stable (within the
No motion parameters) and the zero is within the ZI range. To check the current value, issue the ZI
command without any additional parameters. To change the value, issue the CE command with the
current TAC value and then ZI followed by the new value. See table below.
ZI Initial Zero Range
Master (PC / PLC) sends
LDU XX.X responds
Result
CE
ZI
ZI_1
CE_17
E+00017 (example)
R+00005
OK
OK
Current TAC value is 17
Initial Zero range 5 divisions
Initial Zero range changed to 1division
Calibration commands enabled
Ideas in Measuring ..
TECHNIQUES LIMITED
Page 21
LDU 68 Series Manual
The motion detection facility prevents certain functions from being performed if the weight value is
unstable or ‘in-motion’.This ensures that a new value cannot be set when the weight value is
varying greatly over a short period of time. For a ‘no-motion’ or ‘stable’ condition to be achieved,
the weight signal must not vary by more than NR divisions over the time period NT. If the weight
signal is stable, the relevant bit of the ‘Info status’ (IS) response will be set.
The following functions are disabled if motion is detected:
Calibrate Zero (CZ), Calibrate Gain (CG), Set Zero (SZ) and Set Tare (ST)
5.4 Motion detection commands - NR, NT
This command sets the range within which the weight signal can vary and still be considered
‘stable’. Permitted values are between 0 and 65535. To check the current value, issue the NR
command without any additional parameters. To change the value of NR, issue the NR command
with the new setting. See table below. To save this change to EEPROM use the WP command.
With NR = 2, the weight signal can vary no more than ± 2 d, in the time period NT in order to be
considered stable. Factory default : NR =1
NR No motion range
Master (PC / PLC) sends
LDU XX.X responds
Result
NR
R+00010
No motion range set to 10 d
NR_2
OK
No motion range changed to 2 d
WP
OK
Write parameter to EEPROM
This command sets the time (in milliseconds) over which the weight signal is checked to see if it is
‘stable’ or has ‘no-motion’. The weight signal has to vary by less than NR divisions over the time
period NT, to be considered ‘stable’. Permitted values are between 0 and 65535. To check the
current value, issue the NT command without any additional parameters. To change the value of
NT, issue the NT command with the new setting. See table below. To save this change to EEPROM
use the WP command.
With NT = 500, the weight signal can vary no more than ± NR divisions, in the 500 ms in order to
be considered stable. Factory default : NT = 1000 milliseconds.
NT No motion time
Master (PC / PLC) sends
LDU XX.X responds
Result
NT
T+01000
No motion time set to 1000 ms
NT_500
OK
No motion time changed to 500 ms
WP
OK
Write parameter to EEPROM
Issue 1h
