Bradley Smoker PLC-5 user manual Extended-Local I/O System, Fault Rack

										Troubleshooting	F-9
Extended-Local I/O System						Troubleshooting Guide for the 1771-ALX Adapter Module
		ACTIVE
		ADAPTER
			FAULT
		I/O RACK
			FAULT
Indicators					Description		Probable Cause		Recommended Action
Active	Adapter			I/O
	Fault			Rack
On	Off			Off	Normal indication;
					remote adapter is fully
					operational
Off	On			Off	Local adapter fault (1)		Local adapter not operating; it will		Cycle power to the chassis to clear the
							stay in fault mode until fault is		adapter fault.(2) Replace adapter if fault
							corrected		does not clear.
Off	Off			On	I/O chassis fault 1		Problem exists between:		Cycle power to the chassis to clear a
							•	adapter and module in chassis; the	problem resulting from high noise.2
								module will stay in fault mode until	•	remove and replace all I/O modules one at a
								fault is corrected
										time
							•	shorted printed circuit board runs on
									•	replace adapter
								backplane or I/O module
									• If problem does not clear, something is
										wrong in chassis or I/O module
Blinking	Off			Off	Outputs are reset		Controller is in program or test mode		None
							Local I/O Scanner is holding adapter
							module in fault mode		Fault should be cleared by extended-local
									I/O scanner.
Blinking alternately				Off	Adapter module not		Controller restart lockout switch on		Press chassis reset button to clear lockout
					actively controlling I/O 1		chassis backplane switch assembly		feature or cycle power; if after repeated
					Adapter module in		on(3)		attempts indicators are still blinking, check
					controller restart lockout				that adapter module was reset by
					mode (adapter to				controller/scanner, then immediately
					scanner link is normal)				faulted.
Off	Off			Off	No power or no		Power supply fault		Check power supply, I/O cable and power
					communication.				supply cable connections, and make sure
									adapter module is fully seated in chassis.
On	Blinking			Off	Module placement error		Incorrect placement of high-density		Verify addressing modes and switch
					in extended-local I/O		modules		settings.
					chassis

(1)Cycling power clears the block-transfer request queue. All pending block transfers are lost. Your program must repeat the request for block transfers from the chassis.

(2)If a fault occurs and the controller is in the run mode but is actually operating in the dependent mode, the chassis fault response mode is selected by switch 1 (the last state switch) on the chassis backplane.

(3)The I/O chassis is in faulted mode as selected by switch 1 (the last stare switch) on the chassis backplane.

Publication 1785-UM012D-EN-P - July 2005