Halytech
hydroSpider2 User’s Manual v1.23
Page 76
Appendix A.
SDI-12 / RS-485
This section applies to hydroSpiders that have been factory fitted with the SDI-12 / RS-485 option.
This option removes the OC control and the native DIN2 and AIN2 channels, but adds the capability
to monitor up to 16 inputs. These can be made up of any combination of up to 2 native inputs, 4
system inputs (Battery Voltage, Charger Voltage, System Temperature and Moisture Detector) and
up to 16 intelligent SDI-12 / RS-485 inputs.
Appendix A1.
Input Connections
The following table describes the pins of the hydroSpider’s green I/O and Power connector. All pins
are labelled on the lid of the hydroSpider.
Label
Name
Function(s)
Comment
GND
GND
Ground
Common for all signals
AIN1
AIN1
Analogue 1
(Voltage 0 - 2.4V or
Current 4-20mA)
User selectable
DIN1
DIN1
Switch 1
Counter 1
Active is short to ground
SDI-12
SDI-Data
SDI-12 Data
SDI-12 data wire
485 +
RS485 D+
RS485 Data +
RS-485 differential data wire
485 -
RS485 D-
RS485 Data -
RS-485 differential data wire
SWP
PWR OUT
Switched Power Out
Driven by control 1, max 1A
BATT
PWR IN
External Power In
or Battery
Nominal 12V DC
max 7.2Ah battery
CHG
CHARGER IN
Charger Supply In
15V – 24V 2A DC or
12V Solar Panel
GND
GND
Ground
Common for all signals
SDI-12 / RS-485 interface specific pins that are different from those on the standard hydroSpider are
highlighted in yellow.
Appendix A2.
Connecting Sensors
Both SDI-12 and RS-485 (Modbus) sensors can be daisy-chained to the hydroSpider’s inputs. Each
sensor needs to have a unique address so they can be talked to independently of the other sensors.
SDI-12 sensors must always be powered. The following diagram shows a suggested connection
method for SDI-12 sensors.
Additional sensors should all have a common ground connection, and can share the SDI-12 Data line
by connecting in parallel.
