Rockwell Automation T8433 Trusted TMR Isolated 4-20 mA Analogue Input Module - 20 Channel - Manual (Page 31)

Trusted
TM
Module T8433
Issue 11 Apr 10 PD-T8433 31
5.7. Input Channel Calibration Check
It is recommended that you carry out a check 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.