Teledyne gfc 7000ta operation manual Status LEDs, Relay Board Status LED’s

Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer

9.3.5.3. Zero/Span Valve Options

Any zero/span valve options installed in the analyzer are controlled by a set of electronic switches located on the relay board. These switches, under CPU control, supply the +12VDC needed to activate each valve’s solenoid.

9.3.5.4. IR Source

The Relay board supplies a constant 11.5VDC to the IR Source. Under normal operation the IR source is always on.

9.3.5.5. Status LEDs

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 (see Figure 10-14). They are:

Table 9-2: Relay Board Status LED’s

LED	COLOR	FUNCTION	STATUS WHEN LIT	STATUS WHEN UNLIT
D1	RED	Watchdog Circuit	Cycles On/Off Every 3 Seconds under direct control of the
			analyzer’s CPU.
D2	YELLOW	Wheel Heater	HEATING	NOT HEATING
D3	YELLOW	Bench Heater	HEATING	NOT HEATING
D4	YELLOW	Spare	N/A	N/A
D5	GREEN	Sample/Cal Gas	Valve Open to CAL GAS	Valve Open to SAMPLE GAS
		Valve Option	FLOW	FLOW
D6	GREEN	Zero/Span Gas	Valve Open to SPAN GAS	Valve Open to ZERO GAS FLOW
		Valve Option	FLOW
D7	GREEN	Shutoff Valve	Valve Open to CAL GAS	Valve CLOSED to CAL GAS
		Option	FLOW	FLOW
D8	GREEN	IR SOURCE	Source ON	Source OFF

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