SOMMER MRL-7, User Manual

Page: 15 / 100

14
5.1 Measurement options
The MRL-7 data logger is designed to acquire measurements of the following sensor types:
- Analog sensor with voltage and current output
- Resistive sensors, e.g. wind vanes with potentiometer output
- Sensors with frequency output, e.g. anemometers
- Sensors with pulse output, e.g. tipping bucket rain gauge
- Digital sensors using SDI-12 and Sommer RS-485 protocols
5.1.1 Analog input terminals
The analog input terminals can be configured to different input signals. Table 2 lists the available op-
tion.
Analog input Measurement options
An 1 0 … 2.5V
An 2 0 … 2.5V
An 3
0 … 2.5V
NTC
Resistance > 2kΩ
An 4
0 … 2.5V
0 … 0.3V
Resistance > 1k25Ω
Resistance < 1k25Ω
PT1000
Wind direction / Counter 2b
Either resistance (potentiometer) or pulse counter for encoder
(min. 5V); selected by DIP-switch (see
Appendix E )
Table 2: Analog input terminals
5.1.2 Counter & frequency input terminals
The available counter and frequency inputs are listed in Table 3 .
Analog input Measurement options
Counter 1
Pulse counter (min. 5V), max. frequency 99 Hz; configurable as
pull-up or pull down (see
Appendix E )
Counter 2
Pulse counter (min. 5V), max. frequency 99 Hz; configurable as
pull-up or pull down (see
Appendix E )
Wind speed Dedicated to wind speed only, max. frequency 1 kHz
Table 3: Counter & frequency input terminals