Optiquest iRIS 220, iRIS 320 Sensor Connection Examples, Connecting a Flow Meter or Rain Gauge

53 - iRIS 220 / iRIS 320, V1.19 User Guide

6 Sensor Connection Examples

6.1 Connecting a Flow Meter or Rain Gauge

One of the most common uses for the iRIS is logging data from pulse sources such as flow meters or rain gauges.

Connecting such devices to the iRIS is very simple – wire the switch between the appropriate digital input (DI1 or DI2) and the digital ground (DGND) terminal. Both of the digital inputs provide a “wetting current” for clean contact sources, but transistor switches and active signals (ones that supply a voltage) can also be used. If a transistor switch is used, connect the collector (+) to the digital input and the emitter (-) to the DGND. See section 3.4.5 for details on the digital inputs and setting up the input debounce mode.

Both inputs can be used simultaneously and each input has three associated totalisers, which are viewable from the LCD. See section 5.2.7. These totalisers operate even if the input is not configured as a source to one of the six virtual sensors.

The diagram below shows the typical connection diagram for such an installation. It assumes the use of DI1 as the pulse input channel. The charging source can be any d.c supply from 15V – 30V, including a directly connected solar panel.

TOP

AI4
AI3
AI2
AI1
AGND
5VOP
DI2
DI1
DO2
DO1
SDI-12
DGND
12V+
GND (-)
VIN+	Charging source e.g solar panel
GND (-)

Flow Meter

or

Rain Gauge

BOTTOM

IRIS I/O Connector

The sensor should be configured for the correct channel, scaling and logging regime as described in section

4.3.8.Event mode (sensor mode=2) can be used to reduce the quantity of data logged, especially for rainfall where the actual data density is low.