Rice Lake 720i Programmable Indicator/Controller - Installation Manual - Manual (Page 54)

48 720i Installation Manual
3. Ensure scale is empty, then press Down again
to show the current WZERO value, then press
the
Calibrate softkey to calibrate zero. When
complete, the new A/D count for the zero
calibration is displayed. Press
Enter to save
the zero calibration value and go to the next
prompt (
WVAL ).
4. With WVAL displayed, press Down to show the
stored calibration weight value. Enter the
actual value of the calibration test weight
using the up/down arrows or keypad, then
press
Enter to save the value and go to span
calibration ( WSPAN ).
Note
Note
If unable to change value using
keypad, use the following method to
enter new value:
Use the up/down keys to change
the first digit to desired number. Then use the
key pad to enter the rest of the numbers.
Example: To enter 25000 change the first
number using up/down arrows to 2. Then use
the keypad and enter 5000. The result will be
25000.
5. Place test weights on scale. Press Down again
to show the current WSPAN value, then press
the
Calibrate softkey to calibrate span. When
complete, the new A/D count for the span
calibration is displayed. Press
Enter again to
save the span calibration value and go to the
next prompt (
WLIN ).
6. Five-point linearization (using the WLIN
parameter) provides increased scale accuracy
by calibrating the indicator at up to five
additional points between the zero and span
calibrations.
Linearization is optional: if you choose not to
perform linearization, skip the WLIN
parameter; if linearization values have
previously been entered, these values are reset
to zero during calibration. To perform
linearization, follow the procedure below:
With
WLIN displayed, Press Down to go to the
first linearization point ( POINT 1 ). Press Down
again to show the weight value prompt ( WGT
1 ), then Down once more to show the weight
value. Place test weights on the scale, then use
the numeric keypad to enter the actual test
weight value. Press
Enter to save the value
and move to the calibration ( CAL 1 ) prompt.
Press Down to show the current calibration
value, then press the Calibrate softkey to
calibrate the linearization point. When
complete, the A/D count for the linear
calibration is displayed. Press
Enter again to
save the calibration value and go to the next
prompt (
POINT 2 ).
Repeat for up to five linearization points. To
exit the linearization parameters, press the
Up
key to return to WLIN.
7. The optional rezero function is used to
remove a calibration offset when hooks or
chains are used to hang the test weights.
The rezero function cannot be used
with five-point linear calibration.
• If no other apparatus was used to hang the
test weights during calibration, remove
the test weights and press
Up to return to
the CALIBR submenu.
• If hooks or chains were used during
calibration, remove these and the test
weights from the scale. With all weight
removed, go to the REZERO parameter,
then press
Down to show the current zero
value. Press the Calibrate softkey to adjust
the zero and span calibration values. Press
Enter or Up to return to the CALIBR
submenu.
8. Press Up to return to the SCALES menu, or
press the Save and Exit softkey to exit setup
mode.
4.3 Serial Command Calibration
To calibrate the indicator using serial commands, the
indicator serial port must be connected to a terminal or
personal computer. See Section 2.3.3 on page 7 for
serial port pin assignments; see Section 10.0 on
page 86 for more information about using serial
commands.
Once the indicator is connected to the sending device,
do the following:
1. Place the indicator in setup mode (display
reads CONFIG ) and remove all weight from the
scale platform. If your test weights require
hooks or chains, place the hooks or chains on
the scale for zero calibration.
2. Send the SC.WZERO#1 serial command to
calibrate zero.
3. Place test weights on the scale and use the
SC.WVAL command to enter the test weight
value in the following format:
SC.WVAL#1=vvvvv<CR>
4. Send the SC.WSPAN#1 serial command to
calibrate span.
5. Up to five linearization points can be calibrated
between the zero and span calibration values.
Use the following commands to set and
calibrate a single linearization point:
SC.WLIN#1.V1=vvvvv<CR>
SC.WLIN#1.C1<CR>
The SC.WLIN#1.V1 command sets the test
weight value (vvvvv) for linearization point 1.
The SC.WLIN#1.C1 command calibrates the
point. Repeat using the SC.WLIN#1.Vx and
SC.WLIN#1.Cx commands as required for
additional linearization points.