AEC WD 350 through WD3000 Dehumidifying Dryers - Manual (Page 30)

Run Indicator
The green
Run LED lights when the PLC executes the program and operates normally.
Link Indicator
The
Link indicator is not used.
Error Indicator
The red
Error LED lights when an internal self-diagnosis detects an error and stops PLC
operation (the Run LED is off).
4-6 Level 1 Temperature Controller LED Indicators
888
Process Value Numeric LED
During normal operation, the process value LED on the controller displays the process
temperature at the
TO PROCESS thermocouple. It also lists parameters during setup and error
messages if an error occurs. Press the Mode key once to display the process temperature set
point.
ON
Output LED
The orange On Output LED lights when control output energizes the process air heater.
AL
Alarm LED — High Temperature Alarm
The AL alarm indicator lights when the process air temperature rises more than 25° from the set
point (factory default). The alarm relay in the PLC energizes when this LED lights. The
audible/visual alarm actuates if the dryer is so equipped. All heaters turn off and the blowers stay
on to cool the heaters. You can adjust the alarm value; see Section 6-5 on Page 43 for more
information.
Deviation Indicators
∆ Arrow Up
The arrow up indicator lights when actual temperature is higher than the set point.
In Range
The in-range square indicator lights when temperature deviation is within plus or minus one
percent (±1%) of the set point.
WDMR and WDFR Series Dehumidifying Dryers Page 29