The green LED should be on solid when the JIB is powered. The red LED should flash indicating that it is alive and running. Specific red LED blinking behavior depends on the model of JIB.
Slow blink: JIB is not receiving engine data.
Fast blink (flicker): JIB is receiving engine data
The JS501 may be connected to one or two different engine data busses. They are referred to as J1708 and J1939.
Single blink: JIB is not receiving engine data.
Double blink: JIB is receiving J1708 data.
Triple blink: JIB is receiving J1939 data.
Flicker: JIB is receiving data from both data busses.