Rice Lake IQ plus 310A Installation Manual page 41

J3
Load Cell
Connector
7
EXC –
6
EXC +
5
SHIELD
4
SEN –
3
SEN +
2
SIG –
1
SIG +
J4
Comm & I/O
Connector
IN 1
IN 2
PRN RS232
PRN 20MA
EDP RX
GROUND
EDP TX
b. Communications and Digital Input Cable
2. Set the Simulator to 0.0 mV/V.
3. Send command "CN". Wait for the response "ok".
b. 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. Send command "CR". Wait for the response "ok".
c. 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. Send command "CG". Wait for the response "ok".
(6) Set SW3 to the "Normal" position. Using the load cell simulator, calibrate the instru-
ment (See Section 4) and check for normal operation. In "OPERATE" mode, simulta-
neously press the UNITS key and the hidden key to the left of the ZERO key to display
raw counts. Typical readings for the raw counts are 1680 (–0.5 mV/V), 106450 (0.0
mV/V), 943200 (4.0 mV/V), and 1047800 (4.5 mV/V). All readings typically have 10
counts peak-to-peak noise. Press the hiden key by itself to return to the normal display
mode.
(7) Re-install jumpers JP1 and JP2 if they were removed in step (1).
Normal
SW2
Reversed
a. Load Cell Simulator Cable
Normal
7
SW3
6
Calibrate
5
4
3
2
1
FIGURE 27 – A/D CALIBRATION CABLES
Normal
SW1
Calibrate
1 2 3 4 5 6 7
c. 7-Position Screw
Terminal Block
To
RX
RS232
GND
Terminal
TX
(Optional)
EXC –
EXC +
To
Load Cell
Simulator
SIG –
SIG +
39