Status Leds; I2C Watch Dog Circuitry - Teledyne T300 Operation Manual

Teledyne API – Model T300/T300M CO Analyzer

13.4.4.5. STATUS LEDS

Table 13-4: Relay Board Status LEDs
LED COLOR
D1 RED
D2 YELLOW
D3 YELLOW
D4 YELLOW
Sample/Cal Gas Valve
D5 GREEN
D6 GREEN Zero/Span Gas Valve Option
D7 GREEN
D8 GREEN

13.4.4.6. I2C WATCH DOG CIRCUITRY

06864B DCN6314
Eight LEDs are located on the analyzer's relay board to show the current status on the
various control functions performed by the relay board. They are listed on Table 13-4.
FUNCTION
Watch Dog Circuit
Wheel Heater
Bench Heater
Spare
Option
Shutoff Valve Option
IR SOURCE
Figure 13-15: Location of relay board Status LEDs
Special circuitry on the relay board monitors the activity on the I
D1. Should this LED ever stay ON or OFF for 30 seconds, the watch dog circuit will
automatically shut off all valves as well as turn off the IR Source and all heaters. The
GFC Wheel motor will still be running as will the Sample Pump, which is not controlled
by the relay board.
STATUS WHEN LIT
Cycles On/Off every 3 seconds under direct control of the analyzer's
CPU.
HEATING
HEATING
N/A
Valve Open to CAL GAS FLOW
Valve Open to SPAN GAS FLOW
Valve Open to CAL GAS FLOW
Source ON
Theory of Operation
STATUS WHEN UNLIT
NOT HEATING
NOT HEATING
N/A
Valve Open to SAMPLE Gas Flow
Valve Open to ZERO GAS FLOW
Valve CLOSED to CAL GAS
FLOW
Source OFF
2
C bus and drives LED
317