Specifications

Table Of Contents
INSTALLATION
Page 31 MRC-565 Packet Data Radio Operations and Maintenance
4.1.4.4 Sensor Port
The Sensor port is used as a general purpose Supervisory Control and Data Acquisition
(SCADA) interface requiring limited I/O in lieu of a full data logging capability. Use a mating
cable with a 25-pin male D connector for access to the various functions. For convenience, this
cable may be routed to a terminal block for interfacing to the various sensors and other external
devices. The Sensor Port contains:
SDI-12 Input/output and ground
Four (4) Optical Isolated Discrete Inputs. All 4 inputs share a common ground.
Two (2)Optical Solid State Switches which are normally open.
Six (6)Analog inputs
+12V Current limited to .50 amps
Switched + 12V Current limited to .5 AMP
TX Key Test Point
SP Test Point
A pin out of the Sensor Port is given below.
SENSOR PORT
Pin
Signal
1
Optocoupled input #1 positive
2K Input R, 2 V threshold
2
SDI-12 Data
3
Optocoupled input #2 positive
2K Input R, 2 V threshold
4
Optocoupled input #2 return
5
Optocoupled input #3 positive
2K Input R, 2 V threshold
6
Det RF for Chan #3
7
Optocoupled input #4 positive
2K Input R, 2 V threshold
8
Det RF for Chan #2
9
Ground
10
Solid State Relay #1 +
(.5 Amp rating)
11
Solid State Relay #1 -
12
Signal Presence (SP) 3.3V Logic
13
Solid State Relay #2 +
(.5 Amp rating)
14
Solid State Relay #1 -
15
TX KEY 3.3V Logic
16
+5V Reference (10 ma Max +/- 2%)
17
Analog Input #1 ( 0 to 5 V) ±1%
18
Analog Input #2 ( 0 to 5 V) ±1%