User's Manual

TRAIN CHIEF® II LRCS w/Lightweight OCU OWNER’S MANUAL
95-00-0-xxx Rev 000 3-10 Control Chief Corporation
WATCHDOG SYSTEM
Remote control systems based on the SLC 500™ controller with the Communicator®
module will utilize a multiple feature watchdog safety system. The first watchdog circuit is
built into the wireless Communicator® module and monitors the operation of the module
CPU. Should this watchdog time out, then an automatic interrupt is generated which faults
the SLC 500™ CPU and clears all SLC output tables. An additional watchdog feature within
the module will clear the module I/O image table if communication with the remote unit is
lost.
The High Current Relay/Watchdog module incorporates two (2) additional watchdog safety
systems. Each watchdog safety system consists of a circuit that drives a dedicated output
relay. Each circuit monitors a critical system function to verify proper system operation. The
dedicated watchdog relay outputs are used to control the E-Stop relay in the locomotive
interface panel.
DEVICENET SCANNER MODULE
The DeviceNet scanner module included in this Train Chief® II system provides the
standard field bus data interface to the Control Chief Triad® Module. DeviceNet is the field
bus protocol used in this system. This interface provides for a 2-way data exchange
between the Triad ® processor and the PLC backplane I/O map.
THE CONTROL CHIEF TRIAD® MODULE.
The Control Chief Triad® Module is not part of
the PLC rack assembly, but is directly wired to the PLC through the DeviceNet scanner. This
module consists of three (3) sub units (hence the name Triad) all working together to receive
radio data (radio sub unit), decode and format the data, and transfer the data over
DeviceNet to the PLC (field bus sub unit). This module also includes a safety watchdog sub
unit. This sub unit is monitors various watchdog heartbeats as well as the RF link to ensure
the proper operation of all controller sub systems.