Halytech
hydroSpider2 User’s Manual v1.23
Page 117
Appendix H.
Connecting Sensors
The hydroSpider has two digital channels (DIN1 and DIN2) and two analogue channels (AIN1 and
AIN2).
Digital channels are those which trigger on a transition from one state to another. All digital
channels are based on the closing of a switch connected between a DINx pin and ground.
The hydroSpider2’s analogue channels can each operate as either a voltage input or a pre-calibrated
4-20mA channel
The following sections discuss how different sensor types can be wired up to the hydroSpider.
Appendix H1.
Switches
Switches are connected between a digital input pin and ground. When the switch closes for 3
seconds or more, the hydroSpider recognises a transition in the corresponding Switch channel. A
diagram for connecting a typical switch to the hydroSpider is shown below.
For example
: a switch is to be connected to digital input 2 of the hydroSpider. The switch should be
wired between DIN2 and GND. When the switch closes, DIN2 will be shorted to ground and the
hydroSpider will detect the switch closure after 3 seconds.
Appendix H2.
Counters and event-type
Counter and Event channels make use of the hydroSpider’s digital inputs. When the sensor pulses
and shorts the digital pin to ground, the hydroSpider registers an event and acts accordingly. A
diagram for connecting a pulse output to the hydroSpider is shown below.
For example
: a flow meter is to be connected to digital input 2 as a Utility Meter. The flow meter
must be wired between DIN2 and GND and the channel set up as a Counter type with the “Log
difference in reading” feature enabled. The hydroSpider will detect the flow meter’s pulses and
increment the channel’s count accordingly.
