TM3 I/O Configuration General Description

Introduction

The I/O expansion bus of the bus coupler is formed when you assemble the TM3 I/O expansion modules to the bus coupler.

I/O Expansion Bus Error Handling

When the bus coupler detects a TM3 module in bus communication error it sets the bus to a "bus off" condition whereby the TM3 expansion module outputs, the input image value and the output image value are set to 0. A TM3 expansion module is considered to be in bus communication error when an I/O exchange with the expansion module has been unsuccessful for at least 10 consecutive bus task cycles.

Normal I/O expansion bus operation can only be restored after eliminating the source of the error and performing one of the following:

oPower cycle

oNew application download

oIssuing a controller Reset Warm or Reset Cold command with EcoStruxure Machine Expert.

Match Software and Hardware Configuration

The I/O that may be embedded in your controller is independent of the I/O that you may have added in the form of I/O expansion. It is important that the logical I/O configuration within your program matches the physical I/O configuration of your installation. If you add or remove any physical I/O to or from the I/O expansion bus or, depending on the controller reference, to or from the controller (in the form of cartridges), then you must update your application configuration. This is also true for any field bus devices you may have in your installation. Otherwise, there is the potential that the expansion bus or field bus no longer function while the embedded I/O that may be present in your controller continues to operate.

The Optional Feature for I/O Expansion Modules

I/O expansion modules can be marked as optional in the configuration. The Optional module feature provides a more flexible configuration by the acceptance of the definition of modules that are not physically attached to the logic controller. Therefore, a single application can support multiple physical configurations of I/O expansion modules, allowing a greater degree of scalability without the necessity of maintaining multiple application files for the same application.

You must be fully aware of the implications and impacts of marking I/O modules as optional in your application, both when those modules are physically absent and present when running your machine or process. Be sure to include this feature in your risk analysis.

NOTE: For more details about this feature, refer to Optional I/O Expansion Modules.