On a Yokogawa STARDOM, there are 3 LEDs (HRDY, RDY and CTRL) for indicating various operating state of the STARDOM FCJ / FCN / FCN-RTU. Each of these LED can be either Off, On, Fast Blinking or Slow Blinking.

The table below outlines all the possible combination of the LED states and its associated operational state of the Yokogawa STARDOM.
Note that if you get a combination of LED that is not displayed on the table below, it may be that your DIP switch on the STARDOM is incorrect or the STARDOM FCN/FCJ/FCNRTU has failure.

Xybernetics Yokogawa STARDOM - Status LED HRDY RDY CTRL