Bradley Smoker PLC-5 Remote inputs inactive, Here are two programming methods you can use, Inputs

15-4Preparing Fault Routines

The outputs in the faulted rack remain in their last state or they are de-energized, based on how you set the last state switch in the I/O chassis.

		ATTENTION		If outputs are controlled by inputs in a different rack
				and a remote I/O rack fault occurs (in the inputs rack),
				the inputs are left in their last non-faulted state. The
				outputs may not be properly controlled and potential
				injury to personnel and damage to the machine may
				result. Be sure you have recovery methods.
	Outputs in the controller-resident chassis and in any non-faulted remote rack
	can remain active if a remote I/O rack fault is detected. Make sure to design
	your program so that the system goes to a known state in the event that
	outputs in the controller-resident chassis or non-faulted remote racks are
	controlled by inputs from the faulted remote I/O rack. Your program must be
	able to account for the inputs remaining in their last state or the program must
	monitor the rack fault status bits and reset the input image data table to make
	remote inputs inactive.
	Here are two programming methods you can use:
		• In the very first executable instruction, the program monitors the rack
			fault bits. If any faults bits are set, the program copies zeros (0) to the
			faulted rack’s input image data table. The program must continually
			copy zeros at the beginning of the program scan to the input image table
			as long as the fault condition remains because the controller sets the
			input image bits back to the last state at the end of the program scan.
		• In the very first executable instruction, the program monitors the rack
			fault bits. If any fault bits are set, the program sets the corresponding
			inhibit bit for the faulted rack. The program must then execute a one
			time copy of zeros to the faulted rack’s input image table to reset all
			inputs.
Defining a Fault Routine	You can write multiple fault routine programs and store them in multiple fault

routine files, but the controller runs only one fault routine program when the PLC-5 controller detects a major fault. You can, however, change the fault routine program that is to be run through ladder logic. If you do not specify a program file number, the controller immediately enters fault mode after detecting a fault.

Publication 1785-UM012D-EN-P - July 2005