On-Board I/O Modules

The connections for the eight On-board I/O

modules (Figure 2-4) allow process inputs to be

connected directly to the controllers. They also

connect process inputs and outputs to the Main

Processor by way of the I/O Bus. The input and

output modules can be either AC or DC. The IIS

part numbers for the six different plug-in modules

are listed in Table 2-1 below.

Each On-Board I/O Module Connects to

both the Main Processor and a corresponding

controller (e.g. I/O Module 1 connects to the

controller in slot 1. I/O Module 2 connects to the

controller in slot 2. etc..).

The Main Processor can read inputs and

set outputs. Inputs are used by the control

programs to monitor the status of external

devices. Outputs allow the control programs to

affect the status of external devices.

The controllers can read inputs from On

Board Input Modules. These inputs are used with

control program functions to provide fast

hardware interrupts, typically used to initiate a

motion or motion related event.