Bradley Smoker PLC-5 user manual Effectively Using I/O Memory, Use Application

4-24Addressing I/O and Controller Memory

Effectively Using I/O Memory

The PLC-5 controller automatically allocates both an input and output memory location to each I/O location. I/O modules generally only use either the inputs or the outputs. To more effectively use I/O memory, you can use these methods of placing I/O modules.

Use	Application
2-slot	Install 16-point I/O modules as an input module and output module pair in
	an I/O group. For example, if you place an input module in slot 0, place an
	output module in slot 1.
1-slot	Install 32-point I/O modules as an input module and an output module
	pair in an I/O group. For example, if you place an input module in slot 0,
	place an output module in slot 1.
complementary I/O chassis	You configure complementary chassis with a primary and complement
	chassis pair. You complement the I/O modules I/O group for I/O group
	between the two chassis. The I/O modules in the complementary chassis
	perform the opposite function of the corresponding modules in the
	primary chassis.
	By designating a PLC-5 scanner channel as complementary, you can
	complement racks 1-7. A channel configured for complementary I/O can’t
	scan racks greater than 7. Those PLC-5 controllers that can address rack
	numbers greater than 7 can address these racks on another scanner
	channel which has not been configured as complementary. The remote
	I/O link device (such as a1771-ASB adapter) must also be configured for
	complimentary.
	For more information see the PLC-5 Reference Guide: Configuring
	Complementary I/O for PLC-5 Controllers, publication 1785-6.8.3.

Publication 1785-UM012D-EN-P - July 2005