GE IC695PNC001 User Manual page 82

4
Scan Set I/O for Remote I/O Modules
The Scan Set I/O function of the RX3i CPU requests the scanning of remote modules that are
members of a configured scan set. The Scan Set I/O function operates like a DO I/O function, with
the added ability to identify and group the modules to be scanned. Modules are grouped according
to their configured scan sets. As with the DO I/O function, the Scan Set I/O function
updates/consumes data stored in the local PNC; it does not directly update IO-Devices in remote
nodes.
RX3i CPU Defaults - Inputs
The RX3i CPU defaults input data from remote I/O modules under the following conditions:

the remote module signals its input data is no longer valid (e.g. due to local module fault)

the remote module is extracted from the backplane

the remote module loses power or fails

the PROFINET network connection (Application Relationship) associated with the input data is
lost.
The RX3i CPU defaults the input values of an input module based on the input default state
configured for the I/O Device. Inputs may be configured to either Hold Last State or Force Off
(zero).
If a PNC loses connections to an I/O device, the following actions occur:
1. The CPU defaults the input values of all input modules assigned to it within the IO-Device.
2. The PNC logs a Loss of Device fault in its local log and in the CPU's I/O fault table.
3. The I/O point fault contacts for the I/O references and variables associated with the IO-Device
are set to the faulted state (if point faults are enabled on the CPU).
RX3i CPU Defaults - Outputs
Outputs default when the CPU is no longer providing the data (e.g. when CPU has IO disabled). I/O
modules control their own output defaults based on either their configuration or on a fixed output
default behavior (typically 0) if the module's output default behavior is not configurable.
PACSystems* RX3i PROFINET Controller Manual – December 2011
4-14 GFK-2571A