Samson Trovis 6400 Mounting And Operating Instructions page 42

Ai level (adjustment and calibration)
Zero and span adjustment for the inputs Ai 1 to Ai 4
1. Make the settings required for calibration (see previous section).
2. Access the Ai level as described above.
3. Select the input to be adjusted ( Ai 1 to Ai 4) by pressing the C key. CAL oFF appears on
the display (see "Calibrating the input characteristic" below).
4. Use a highly-accurate adjustment device to adjust the initial value of the input signal range.
When the input signal is within the adjustment range, three black bars appear in the left
bottom corner of the display. In addition, the selected input, e.g. Ai 1 and AdJ (for adjust)
alternate in the lower line of the display.
5. Press A key to accept the zero point adjustment. 0.0 appears in the upper line of the
display.
6. Use a highly-accurate adjustment device to adjust the maximum value of the input signal
range (span adjustment). When the input signal is within the adjustment range, three black
bars appear in the right bottom corner of the display field. In addition, the selected input,
e.g. Ai 1 and AdJ (for adjust) alternate in the lower line of the display.
7. Press A to accept the span adjustment. 100.0 appears in the upper line of the display.
8. Repeat steps 3. to 6. to adjust zero and span for the next input or exit the Ai level (see
above).
Calibrating the input characteristic via 5 coordinates
The five coordinates for the calibration curve are set at 0; 25; 50; 75 and 100 % of the input
signal. For an input signal in the range from 4 to 20 mA, these coordinates are, for example,
4; 8; 12; 16 and 20 mA.
Proceed as follows:
1. Make the settings required for calibration.
2. Access the Ai level as described above.
3. Press C key until CAL oFF appears on the display.
4. Press A key. "on" flashes in the upper line of the display.
5. Press A key until "on" stops flashing (approx. 5 s).
6. Press C key. Ai 1 for input 1 and CAL alternate on the display.
7. Select the desired input (Ai 1 to Ai 4), using the C key.
8. Use a highly-accurate adjustment device to set the input signal to 0 %. In the above
mentioned example, this would be 4 mA. When the input signal is within the calibration
range, a scale (0 to 100 %) comes up at the bottom of the display and two black bars
appear over the valid value (0 %). CAL and the selected input alternate in the lower line
of the display.
9. Press A key to accept the first coordinate value.
10. Repeat steps 8 and 9 in order to set the other four coordinate values (25; 50; 75; 100 %)
one after the other.
11. Repeat steps 7. to 10. for the next input or exit the Ai level by pressing the F key.
Note:
The inputs must be re-calibrated in the Ai level after exchanging the EPROM or the input board.
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Operation