Rockwell Automation T8431 Trusted TMR 24Vdc Analogue Input Module - 40 Channel - Manual (Page 29)

Trusted
TM
Module T8431
Issue 16 Sep 11 PD-T8431 29
5.7. Input Channel Calibration Check
It is recommended that you carry out a check at 2 yearly intervals on the input channel calibration. This
check will detect long term drift and any inaccuracy as a result. It requires a three point check as
follows:
Inject a signal to each input channel in turn using the following values and check through the
workbench that the reading is as shown below:
• 4 mA signal should give a 0% of full scale reading
• 12 mA signal should give a 50% of full scale reading
• 20 mA signal should give a 100% of full scale reading
5.8. 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 enforce 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 IEC1131 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
dynamic change over data (COD). The previous standby module then becomes the active
module and the original module becomes standby. If the currently active module does not
successfully complete the self-tests, the TMR Processor will revert it to the standby state,
and the module in the maintain state will revert back to the active state.
• When both Module Removal switches are opened on an active module, regardless of the
module fault status, the TMR Processor will treat it as a request to perform an
active/standby changeover.