CONTREX CX-1200 - Manual (Page 87)

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Analog Output (current):
1. Connect a current meter in series with a 250 Ohm resistor between pins 9 and 11 with the
positive lead on pin 9 (pin 11 is common). Connect the meter in series with the load.
2. Set AO Mode (CP-291) to “Current” (2).
3. Set Analog Cal Sel (CP-461) to AO (3) to Select AO for calibration.
4. Set Analog Cal Ref (CP-462) to “A” (1) to select point A.
NOTE: The old calibration data will be overwritten.
5. Set Analog Cal EN (CP-460) to “On” (1) to start calibration.
6. Adjust AO Bit Set (CP-464) until the meter reads the current you want to set for point A.
This is generally your smallest current point. A 4 milliamp setting requires about -14450 bits,
0.5 milliamps about -24000 bits and 1.0 milliamps about -22600. For 4 milliamps, start with
about -14300 and use the incremental scroll key.
7. Enter the exact current measured by the meter into AnalogRef Val (CP-463).
8 Set Analog Cal Ref (CP-462) to “B” (2) to select point B.
9. Adjust AO Bit Set (CP-464) until the meter reads the voltage that you want to set for point
B. This is usually your largest current point. A 20 milliamp setting requires about 29300 bits,
10 milliamps about 1940. For 20 milliamps, start with about 29200 and use the incremental
scroll key.
10. Enter the exact current measured by the meter into AnalogRef Val (CP-463).
11. Set Analog Cal EN (CP-460) to “Off” (0) to disable further calibration.