Transfer Between Active And Standby Modules - Rockwell Automation Trusted TMR Product Overview

Trusted TMR 120 Vdc Output Module – 32 Channel

5.6. Transfer between Active and Standby Modules

The TMR Processor is responsible for managing a pair of I/O Modules through an
Active/Standby changeover. The following rules apply to Active/Standby changeovers,
though the TMR Processor and not the I/O Module enforces them:
• The user must define the primary, and optionally the secondary, I/O Module location
for each I/O Module pair. Each primary module location must be unique and is
defined as part of the complex equipment definition within the IEC 61131 TOOLSET.
Secondary module locations can be unique or shared between multiple secondary
modules and are defined within the Module's section within the System.INI file. The
system will automatically determine the secondary module position if the primary
module is installed and is operable.
• On initial start-up, if the primary module is installed, it will become the Active
Module by default. If the secondary module has been defined within the System.INI
file and no primary module is present, and if the secondary module location is
unique, the secondary module will become the Active Module by default. If the
secondary module is installed with no primary module present, and the secondary
module location is not unique (as in a SmartSlot configuration), then NO Module for
that Module pair will become Active.
• In order for a Module to become the Active Module, the TMR Processor will verify
that the Module is the correct I/O Module type and that both Module Removal
switches are closed. At this point the I/O Module is configured and eventually placed
in the Active state.
• A Module in the Active state should never be removed.
• When a fault occurs on the Active Module, the TMR Processor will be informed.
Once it becomes aware of the fault, the TMR Processor will attempt an
Active/Standby changeover.
• An Active/Standby changeover starts with the TMR Processor checking to see if a
Standby I/O Module is installed. If no Standby I/O Module is available, the TMR
Processor will continue to utilise the Active Module and will continue to check for an
available Standby I/O Module. Once a Standby Module is found, the TMR Processor
will verify that the I/O Module is of the correct type, that both Module Removal
switches are closed, and that the I/O Module is a part of the correct Module pair by
using the SmartSlot link. At this point, the TMR Processor will configure the Standby
I/O Module with the same configuration information as the currently Active I/O
Module and place the Standby I/O Module into the Standby state. The Active
Module is then placed in the Maintain state (which suspends field loop testing), and
any Module specific changeover data is transferred. The educated light flashes
amber before the Active/Standby changeover takes place, to indicate transfer of
Rockwell Automation Publication ICSTT-RM281P-EN-P (PD-T8471)
5. Fault Finding and Maintenance
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