Linear Output
The optional linear output terminal provides either a 0-5 Vdc, 0-10 Vdc or 4-20 mA signal to the automation system to represent the
degree of pollution. This signal is temperature compensated to provide an accurate and reliable method of tracking the air contaminants.
The output signal type is selected via clearly marked jumpers on the PCB. The output voltage or current span represents a level of
pollution between 0 and 100 %.
Relay Output
The optional relay output terminals provide a Form C relay contact for on/off status indication. The relay has two operational modes
which may be menu selected.
The relay may be set to operate in conjunction with the ASO signal which has four distinct levels (OK, LOW, MID and HIGH). In this
mode the relay trip level is set to be either LOW, MID or HIGH and when the ASO pollution level reaches the trip level the relay will
be energized. For example, if the relay trip level is set to HIGH then the relay will energize whenever the ASO indicates a HIGH
pollution level.
The relay may also be set to operate in conjunction with the analog Linear output signal if this option is installed. In this mode the relay
trip level can be set from 1 to 4 Volts (wrt-output) on the 0-5 Vdc output range (20 – 80 % pollution). The other output signal ranges
are scaled accordingly as shown in the following section. In this operation mode the relay will energize when the linear output signal
exceeds the preset trip level. The amount of relay hysteresis may also be programmed via the menu so the relay will turn on when the
linear output is Relay Level + ½ Relay Hysteresis and turn off at Relay Level – ½ Hysteresis.
Configuration Menu
The Configuration Menu is used to set the operation mode, relay modes and for calibration. This menu is accessed during normal
operation by pressing and holding the <DOWN> key and then pressing the <UP> key (then release the keys). This menu is explained
below.
<DOWN> (hold key)
<UP>
Release keys
(enters configuration menu)
1.
Manual/Auto
- selects the operating mode, use the <UP> or <DOWN> key to select, if the AUTO
LED is lit then Auto Mode, if AUTO LED is not lit then Manual Mode, the OK and
LOW LEDs flash to indicate this step
<MODE>
2.
Relay Select Mode
- sets the relay operating mode as described above, the <DOWN> key selects ASO
mode (indicated by a flashing HIGH LED) and the <UP> key selects the Linear
mode (indicated by a flashing MID LED), the Linear mode will only function
if the hardware option is available
<MODE>
3.
Relay Level
- if ASO mode is selected can select either LOW, MID or HIGH levels (indicated on
LEDs) by using <UP> or <DOWN> keys
- if Linear mode is selected can set the level between 1 and 4 V on the 0-5 Vdc range
(indicated as a binary number on LEDs) and also output to the Linear output terminal
<MODE>
4.
Relay Hysteresis
- if Linear mode the relay hysteresis can be set from 0 to 0.606 V on the 0-5 Vdc output
range to prevent relay chatter, this is shown on the LEDs and output to the Linear
output terminal
<MODE>
5.
Air Offset Calibration
- this menu item allows calibration of the air quality sensor but is not usually adjusted
by the installer, the calibrated sensor value is output on the ASO terminal.
<MODE>
6.
Normal Operation
- flashes all LEDs and the device returns to normal operation
