Micro-Master Touch User Guide
99
© 2014 Toro Australia Pty Ltd
Ver 1.2, June 2014
14.6
Digital Sensors
14.6.1 Overview and Operation
The Micro-Master Touch supports up to 160 independent digital sensors. A digital sensor can be
used as a general purpose sensor or used as an input to Rules.
A common application of the digital sensor function is to monitor the condition of a normally open,
high/low pressure switch (or flow switch) installed in the system mainline. In the event of a valve not
opening (high pressure and no flow) or a pipeline rupture (low pressure and high flow) the controller
will permit the condition to persist for a pre-set time. If this time exceeds the scan delay time, and
the digital sensor is allocated to the Skip Input for a program, the controller will then advance to the
next programmed station or group.
Each digital sensor can be named and can be enabled or disabled.
Digital Sensor Operation
When a digital sensor is enabled, the digital input is monitored every second. If the digital sensor
detects the input is closed (shorted to the GND terminal), the digital sensor is active or triggered. If
the digital sensor detects the input is open circuit, the digital sensor is idle, or untriggered.
The digital sensor operation is shown in Figure 71.
Idle
Active /
Triggered
Input closed to GND
Input open circuit
Figure 71 - Digital Sensor Operation Schematic
Digital Sensor Parameters
Digital Sensor Scan Delay
Digital Sensors incorporate a scan delay. When a digital input is physically closed or opened, the
sensor system will wait for the specified scan delay time before reporting the digital input has
changed. This scan delay is used to allow time for systems to stabilise after a change in conditions.
Depending on the configuration of the irrigation system, the system may need a period of time to
stabilise after initial start-up, mainline filling, air evacuation etc.
