User`s manual

User’s Manual
Arctic GPRS Gateway 26 Viola Systems Ltd.
6. I/O Interface (optional)
This chapter describes the hardware and related software (for interface extensions).
There are two types of I/O boards:
IO-8-2 8 general purpose digital inputs, 2 digital outputs
IO-8-1-1 8 general purpose digital inputs, 1 digital output and 1 analog input for voltage
measurement or monitoring
Digital Inputs (IO-8-2 and IO-8-1-1 only)
For general purpose digital I/O interfacing the Arctic includes eight digital inputs which all share a
common reference pin. The inputs are optically isolated and work with AC voltage levels from 5 to
60 V and this range is guaranteed to be interpreted as a logical high state. AC voltage levels less than
2 V are interpreted as a logical low state. The schematic of one digital input is shown in the figure
below.
In the figure INPUT refers to one of the eight Digital Input n -pins and IN_COMMON refers to Digital
Input Common -pin in the I/O connector’s pin description table shown below:
P
in # 8-1-1 model 8-2 model (default)
1 DC out DC out
2 Digital input 1 Digital input 1
3 Digital input 2 Digital input 2
4 Digital input 3 Digital input 3
5 Digital input 4 Digital input 4
6 Digital input 5 Digital input 5
7 Digital input 6 Digital input 6
8 Digital input 7 Digital input 7
9 Digital input 8 Digital input 8
10 Digital input common Digital input common
11 Digital output 1A Digital output 1A
12 Digital output 1B Digital output 1B
13 Analog input 1+ Digital output 2A
14 Analog input 1- Digital output 2B
15 DC GND DC GND
Digital Outputs (IO-8-2 and IO-8-1-1 only)
The digital outputs of the Arctic are 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