210 SERIES SIGNAL MONITOR
OPERATIONS MANUAL
Eberle Design Inc. Page 2
Section 2
GENERAL DESCRIPTION
2.1 BASIC FUNCTIONS
The Signal Monitor is a device used in a traffic controller assembly to monitor traffic signals at an
intersection for conflicting proceed indications caused by malfunctions of the controller, load switches,
field wiring and loads, or miss-wiring of the cabinet. The Signal Monitor also provides error sensing of
the cabinet 24VDC supply and monitors the controller Watchdog output. The Signal Monitor is directly
interchangeable with a standard model 210 Signal Monitor and complies with all specifications outlined
in Chapter 4 (Model 210 Monitor Specifications) of the Caltrans Traffic Signal Control Equipment
Specifications (January 1989) and TEES March 12,2009.
When triggered by the detection of a fault condition which exists longer than the minimum period, the
Signal Monitor will enter the fault mode causing the Output relay contacts to close and enabling the
Stop-Time output to the controller. The cabinet assembly should be wired such that the closure of the
Output relay contacts will cause an automatic switching of the field signal outputs from normal operation
to flashing operation. The Signal Monitor will then display the appropriate fault indications and will
remain in this fault mode until a reset command is issued.
2.1.1 CONFLICT MONITORING
The Signal Monitor is capable of monitoring 16 channels. Each channel consists of a Green and Yellow
field signal input. A Program Card is provided for assigning conflicting channels and inhibiting Yellow
monitoring for required channels. The Signal Monitor detects the presence of conflicting Green or
Yellow signals on the AC field terminations between any two or more channels assigned to conflict on
the Program Card. The monitoring circuitry is capable of detecting either full wave or positive and
negative half-wave field signal outputs at the specified voltage levels.
2.1.2 24VDC MONITORING
Sensing of the cabinet 24VDC supply is provided as specified in Section 4.2, Chapter 4 of the Caltrans
Traffic Signal Control Equipment Specifications. When the 24VDC input falls below the specified
voltage levels the Signal Monitor will enter the fault mode causing the Output relay contacts to close
and enabling the Stop-Time output to the controller. See Section 8.1.3.
2.1.3 CONTROLLER WATCHDOG MONITORING (WDT ERROR)
Sensing of the controller Watchdog output is provided as specified in Section 4.3 of the Caltrans Traffic
Signal Control Equipment Specifications. When a logic transition is not sensed for the specified period
(see Section 8.2) the Signal Monitor will enter the fault mode causing the Output relay contacts to close
and enabling the Stop-Time output to the controller.
An AC Line brownout condition will reset the WDT ERROR fault mode when the AC Line is restored.
The WDT Error indicator will remain illuminated until a Reset command is issued via the front panel
RESET button or External Reset input. This indicates to the technician that a WDT Error occurred but
was cleared by an AC Line brownout.
To Next Page
Loading...
Need help?
General