Bradley Smoker user manual Transferring Data, PLC-5/40L and -5/60L I/O Scanning and Update

8-4Communicating with Extended-Local I/O

Transferring Data

•You cannot configure more than one rack to have the same starting rack number and module group; that is, you cannot use chassis to chassis complementary I/O.

Follow these guidelines when you plan your extended-local I/O system.

•Do not configure controller input interrupts (PIIs) for inputs in an extended-local I/O chassis. The PII inputs must be in the controller-resident local I/O rack.

•You can either use 32-point I/O modules and any addressing method or use 1771-IX or -IY modules and any addressing method in extended- local I/O racks. You must specify the type of I/O modules you are using by setting the configuration plug on the extended-local I/O adapter.

•If you need to use a thermocouple module and 32-point I/O modules in the same I/O chassis, use the 1771-IXE module.

The PLC-5/40L or -5/60L controller can scan controller-resident I/O, extended local I/O, and remote I/O. The following figure shows how a PLC-5/40L or -5/60L controller accomplishes I/O scanning and update.

PLC-5/40L and -5/60L I/O Scanning and Update

Extended	Input			Input	Processor-
Local		I/O Image Table			Resident
	Output			Output
I/O					Local I/O
I/O Image Table Update		Output	Input
Synchronous to
program scan
(during housekeeping)		Remote
		I/O
		Buffer
Remote I/O		Input	Output
Buffer Update
Asynchronous to		Remote I/O
program scan		Link

Publication 1785-UM012D-EN-P - July 2005