User's Manual
Arctic GPRS Gateway
Firmware Version 5.0.7
44
Document Version 1.6
Pin #
8-2 model (default)
15
DC GND
6.2
Digital Output (IO-8-2)
The digital output of the Arctic is optically isolated and can be used for
controlling low current external devices. The output is a CMOS relay which is
protected by a PTC type fuse. The output is capable of handling a continuous
current of 50 mA maximum at an ambient temperature of 20°C. In these
conditions the output relay ON resistance together with the resistance of the
fuse is typically about 50
Ω
which results in a 2.5 V loss across output pins with
a full load current of 50 mA. The output schematic is shown in the figure 27.
Figure 31. Schematic Digital Output
In the figure, OUT_A and OUT_B refer to Digital Output nA and Digital Output
nB pins, respectively, in the I/O connector.
Note!
Absolute maximum voltage across digital output pins is 30 V. Voltage levels
above this value may cause permanent damage to the PTC fuse.
6.3
DC Output
The input voltage to the DCIN connector is circulated back to the I/O
connector of the Arctic. See the I/O connector’s pin description table shown
in Chapter 6. This DC output can be used, for example, together with digital
outputs in order to simplify external circuitry and wiring.
6.4
Analog Input (IO-8-1-1 only)
The Arctic models with an optional analog input have a 12-bit A/D converter.
The input is galvanically isolated and is capable of measuring analog signals
up to 60 V, making it ideal for general purpose voltage measurement or
control.
The analog input is unipolar and the pins are designated as Analog Input+ and
Analog Input– in the I/O connector’s pin description table shown in Chapter 3.
Note!
Although the input is protected against reverse polarity and overvoltage the
inputs should not be subjected to voltages exceeding the specified 0 to 60 V
range. The absolute maximum voltage between input pins is ±100 V.
