Repair Information - Johnson Controls IOM2721 Installation Manual

Table 8: Status LEDs and description of LED states
LED label LED color
POWER Green
FAULT Red
SA/FC BUS Green
EOL
Amber

Repair information

If an expansion module fails to operate within its
specifications, replace the expansion module. For a
replacement expansion module, contact your Johnson
Controls representative.
14 IOM2721 Input/Output Module Installation Guide
Normal LED state Description of LED states
Off Steady = No Supply Power or the expansion module's polyswitch/resettable
fuse is open. Check Output wiring for short circuits and cycle power to expansion
On Steady
module.
On Steady = Power Connected
Off Steady = No Faults
Off Steady On Steady = Device Fault
Blink - 2 Hz = Download or Startup in progress, not ready for normal operation
Blink - 2 Hz = Data Transmission (normal communication)
Blink - 2 Hz Off Steady = No Data Transmission (N/A - auto baud not supported)
On Steady = Communication lost, waiting to join communication ring
On Steady = EOL switch in ON position
Off (Except on
terminating devices)
Off Steady = EOL switch in OFF position