Campbell Scientific AL200 ALERT2 Encoder, Modulator, and Sensor Interface - Manual (Page 13)

AL200 ALERT2 Encoder, Modulator, and Sensor Interface
RS-232 Port
DCE
Configurable baud rates, parity, stop bits, and timeout
ElA/TIA-232 and V.28/V.24 Signaling
± 15kV ESD protection
Test Button
The test button located in the lower left hand corner of the AL200 serves
two functions. Pressing it for three to six seconds will trigger a test
transmission containing the latest data available to the AL200. Pressing
the button for longer than 6 seconds will cause the AL200 to generate a
test tone and sustain it for 5 seconds. If the AL200 has been configured as
a datalogger peripheral, only the test tone functionality is active.
Analog Radio Interface
Removable screw terminal connector, 0.15” pitch
Transmit only
Transmit Audio (Tx), 100 – 1000 mV peak-to-peak, software adjustable
Switched Voltage (SW12V), switched supply voltage, 1.8 A at +70°C
Sensor I/O
Removable screw terminal connector, 0.15” pitch
Switch closure (P1)
Internally pulled up to 5 V
16-bit counter
3.3 ms time constant for debounce
5 ms minimum closed time, 6 ms minimum open time
Single-ended analog (SE1)
16-bit Adc
0-5 Vdc
± 12 mV accuracy
80 µV resolution
50 dB rejection at 60 Hz
Software configurable as millivolt or milliamp input
Precision 100 Ω current sense resistor when configured for
milliamp input
Digital I/O (C1)
Software configurable as status (high/low) or SDI-12 input
Status Low 0 to 1.4 Vdc, High 3.5 to 5.0 Vdc
SDI-12 limited to 1 address, 1 value
Transient voltage surge (TVS) and gas discharge tube (GDT)
protected
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