Indications And Outputs; Alarms; Apm Fault; Clean Window/Dirty Chamber - Emerson Net Safety Millennium Reference Manual

3.2

Indications and outputs

Table 3-1:
State
Main menu entered
Normal operation
Startup delay
Dirty optics
Particulate present
Fault Condition
Updating APM Sensor
3.3

Alarms

3.3.1

APM fault

To ensure proper response, the Millennium features self-testing circuitry that continuously
checks for problems. When power is applied, the system automatically begins a test to
ensure proper functionality.
During normal operation, the transmitter continuously monitors the signal from the
internal APM source. If the transmitter determines that the APM program is not running
correctly and reset of the APM sensor will occur.
3.3.2

Clean window/dirty chamber

Over an extended period, oily film or particulate build-up on the sensor window may
obscure the infrared (IR) detector. When dirty, the clean window alarm will trip, the
message Dirty Chamber displays, the Status LED will flash fast red and the current output
will be 3.3 mA. Refer to
on cleaning the APM window.
Transmitter indications
Current Output
3.0 mA
4.0 mA
3.0 mA
3.3 mA
20 mA
2.5 mA
3.0 mA
Section 4.3.2
Status LED
Solid green
Green blip
Slow red flash
Fast red flash
Red blip
Fast red flash
Slow red flash
to define the clean window sensitivity and
Operation
Display
Main menu items
Clear
Start delay
Dirty chamber
Alarm
Fault
Busy
Section 5.2
23