Aalborg OSS-2 Optical - Manual (Page 8)

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6. OPERATING INSTRUCTIONS
The Optical Sensor Switch requires a +12VDC power supply with a minimum cur-
rent rating of 250 mA. During initial power up of the Optical Sensor Switch with
no flow conditions the red LED on the retro reflective sensors will be “On”. This is
an indication that power is on and the sensors are ready for operation. When
alarm conditions become “true”, the red LED on the top of the retro reflective sen-
sors goes to “Off”. The retro reflective sensors can be positioned in any position
along the flow meter tube, except directly in front of each other.
6.1 DIP switch configuration
In order to activate the alarm sensors the corresponding switch has to be
installed in the “On” position on the Configuration DIP switch (see Figure 6.1).
Each sensor can be separately set for Momentary or Latch operation. In addition
the Relay and Buzzer can be configured individually. If for example DIP switch
SW1 is set to “On”, when the left retro reflective sensor is active (Alarm
Condition), the relay and green LED (on left side of the D-connector) will be ener-
gized in the LATCH mode. They will stay in the energized state without any con-
ditions (even if the flow rate changes and the retro reflective sensor have become
inactive) until the RESET button is pressed or external RESET TTL signal is
applied. If momentary mode is set (DIP switch SW3 is set to “On”) the relay and
green LED will be energized only when the left retro reflective sensor is active
(Alarm Condition). The same is true for Buzzer settings.
All Switches Off – Disable Alarm (LED, Relays and Buzzer).
WARNING: Do not install the sensors closer than 10 mm from one
another. Doing so may trigger a false alarm condition. ƽ
ALARM DIP SWITCH CONFIGURATION
LEFT ALARM RIGHT ALARM ACTION WHEN SWITCH IS “ON”
SW1 SW5 LED and Relay are On (LATCH)
SW2 SW6 BUZZER is On (LATCH)
SW3 SW7 LED and Relay are On momentary (FOLLOW SENSOR)
SW4 SW8 BUZZER is On momentary (FOLLOW SENSOR)
Figure 6.1, Optical Sensor DIP Switch Configuration.
Each Optical Sensor Switch is shipped from the factory with the retro-reflective
sensors aligned and does not require additional adjustment of the focus distance.
It may be necessary or desirable to perform realignment of the sensors if the flow
tube was replaced or reinstalled (see p. 6.2).