A/D Calibration; Required Equipment For A/D Calibration; A/D Calibration Procedure - Rice Lake IQ plus 310A Installation Manual

7.3 A/D CALIBRATION

This procedure is required following replacement of the A/D Converter (ADC) or the EEPROM. When the ADC
and/or EEPROM are replaced, performing this procedure may be necessary in order for the ADC to operate.
Implementing this procedure assures that the ADC will operate within its stability specifications. This procedure
requires specialized test equipment and cables, and should be performed only by qualified personnel.

7.3.1 REQUIRED EQUIPMENT FOR A/D CALIBRATION

• A Load Cell Simulator with range of 0 to 5.0 mV/V in 0.5 mV/V increments.
• Two test cables wired according to the schematic in Figure 27.
• An RS232 terminal (optional).

7.3.2 A/D CALIBRATION PROCEDURE

(1) Remove (if installed) jumpers JP1 and JP2 from the main circuit board.
(2) Connect the load cell simulator Cable to J3 on the main circuit board. Connect the
communications and digital input cable to J4.
(3) Set the Operate/Setup Switch to Setup. Set SW1 to "Normal", SW2 to "Normal" and
SW3 to "Calibrate."
(4) If not using an RS232 terminal, follow steps (4)a through (4)d. If using an RS232
terminal, skip to Step (5).
a. Press Gross/Net and Units (Test) keys simultaneously. "A/D N/R" is displayed.
b. A/D Non-Ratiometric Calibration (calibrates the ADC to eliminate internal non-
ratiometric errors):
1. Set SW1 to the "Calibrate" position and SW2 to the "Normal" position.
2. Set the Simulator to 0.0 mV/V.
3. Press the Tare Key. "A/D R" is displayed.
c. A/D Ratiometric Calibration (calibrates the ADC to eliminate internal ratiometric
errors and to establish the minimum load cell signal):
1. Set SW1 to the "Normal" position and SW2 to the "Reversed" position.
2. Set the Simulator to 0.5 mV/V.
3. Press the Tare key. "A/D G" is displayed.
d. A/D Gain Calibration (standardizes the ADC full-scale range):
1. Set SW1 and SW2 to the "Normal" positions.
2. Set the Simulator to 4.5 mV/V.
3. Press the Tare key. The unit re-initializes and returns to "SETUP".
(5) If using an RS232 terminal, follow steps (5)a through (5)c. If using the keyboard, skip
to step (6).
a. A/D Non-Ratiometric Calibration (calibrates the ADC to eliminate internal non-
ratiometric errors):
1. Set SW1 to the "Calibrate" position and SW2 to the "Normal" position.
38