Vaisala Indigo300 - Analog Output Overrange Example; Figure 26 Analog Output Overrange Behavior Example

6.3.1 Analog output overrange example
This example describes the analog output overrange behavior when an output uses a range of
0 ... 5 V, scaled to 0 ... 200 000 ppm (= 0 ... 20 %) CO
2
. The error output level is set to 6 V,
clipping limit is set to 5 % overrange, and error limit is set to 10 % overrange. CO
2
concentrations (ppm) are indicated for the clipping point and error limit point.
Output
voltage (V)
Time
6.00
In error state at
>220000 ppm
(200000 ppm + 10%)
5.00
5.25
Clipped at
210000 ppm
(200000 ppm + 5%)
Regular
measurement
Output clipping limit
Error level
Figure 26 Analog output overrange behavior example
• When the measured CO
2
rises above 20 %, the output rises above 5 V.
• The output keeps rising until the measurement is 21 %CO
2
, at which point the probe
outputs 5.25 V.
• If the CO
2
level rises above 21 %CO
2
, the output still remains at 5.25 V.
• If the CO
2
level rises above 22 %CO
2
, the output enters the error state, which is 6 V for the
0 ... 5 V output.
Chapter 6 – Configuring analog outputs
45