Alcolizer WM4 - Relays

REF: WM4 User Manual V7.docx Page 34 © Alcolizer Technology
13 Relays
The WM4 is equipped with three relay outputs on the circuit board and their outputs can be
configured to trigger in response to a breath test result. To access the Relays Menu refer to
paragraph 7.1.
If a relay output is enabled, the relay will trigger for the specified duration if the breath test
result is greater than or equal to the minimum value and less than the maximum value.
The relay outputs are independent of each other. The minimum and maximum values can
overlap such that one, two, or three relays can be triggered simultaneously.
If a new breath test result is calculated while a relay output is asserted from the previous
test, the relay takes the value required by the new test.
13.1 Hardware
The relays outputs are labelled on the circuit board as Relay1, Relay2 and Relay3.
Each relay output has three terminals:
• COM: Common connection.
• NC: Normally Closed, the COM/NC circuit is closed (passes current) when the relay
is not triggered and open when the relay is triggered.
• NO: Normally Open, the COM/NO circuit is open when the relay is not triggered and
closed (passes current) when the relay is triggered.