Rockwell Automation T8444 Trusted Pulse Generator and Monitoring Module - Manual

SDS-8444
Trusted
TM Industrial Control System
Trusted TM Pulse Generator and Monitoring Module-T8444
Issue 1 Sep 2006
FRONT PANEL
DESCRIPTION
The Trusted TM TMR Pulse Generator and Monitoring
module interfaces through special Thyristor Drivers, to
two Stepper Motors, which form an integral part of a
damper rod control system. The module is based upon
the Trusted
TM T8461 Digital Output module. Feedback
of Thyristor activation and rod position is provided by
the module as a % Movement figure and a series of
fault signals. Triplicated diagnostic tests are performed
throughout the module in order to locate and
annunciate hardware failures. Inputs are treated as
analogues and are fully tested by the nature of their
operation. Fault tolerance is achieved through a Triple
Modular Redundant (TMR) architecture within the
module.
The module has been configured to provide the control
and interlock requirements for a high power stepper
motor control system which is used to position Damper
Rods in a Nuclear reactor. The Module has 6 pulse
outputs, 12 pulse inputs and 2 control signals per motor
drive.
The design concept maintains the advantages of TMR
systems while retaining a simple implementation of a
Damper Rod control system by the use of redundant
paths. It is designed to maintain the last controlled rod
state on failure wherever possible.
The module generates a series of waveforms which
rotate a stepper motor in either a clockwise or anti
clockwise direction. The phasing of the outputs
determines the direction of rotation while the frequency
determines the speed.
Extensive diagnostics provide the automatic detection
of module faults. The TMR architecture of the module
and the diagnostics performed ensure the validity of all
critical circuits. Using the TMR architecture provides a
Fault Tolerant method to withstand the first fault
occurrence on the module and continue normal control
without interruption in the system or process. Module
faults are reported to the user through visual indicators
on the front panel of the module and through status
variables which may be automatically monitored in the
application
programs and external system
communications interfaces.
FEATURES
Two Stepper Motor
controls
Special control
algorithms and fault
diagnostics resident
within the module
Bi-directional Fast and
slow movement
Emergency stop and
hold facility
Rod position indication
Thyristor driver fault
indications
ESD rod release
2500V dc optical
isolation barrier
Automatic over-current
protection (per channel),
no fuses required
(outputs)
Front panel status LEDs
for each point indicate
status and field wiring
faults
Front panel module
status LEDs indicate
module health and
operational mode
(Active, Standby,
Educated)
T2V Certified IEC 61508
Sil 3