Teledyne T200 Operation Manual page 315

Teledyne API – T200 NO/NO
13.3.4.2. WATCHDOG CIRCUITRY
13.3.4.3. VALVE CONTROL
06858E DCN7057
/NO Analyzer Operation Manual
2 X
The most important of the status LED‟s on the relay board is the red I
LED. It is controlled directly by the analyzer‟s CPU over the I
on the relay PCA watches the status of D1. Should this LED ever stay ON or OFF for
30 seconds, indicating that the CPU or I
Circuit automatically shuts all valves and turns off all heaters.
The relay board also hosts two valve driver chips, each of which can drive up four
valves. The main valve assembly in the T200 is the NO/NO
component mounted right in front of the NO

These two valves are actuated with 12 V supplied from the relay board and under
the control of the CPU through the I
Additional valve sets also controlled by the CPU via the I
be included in the T200 (see Table 1-1 and Sections 3.3.2.3, 3.3.2.4, and 3.3.2.5 for
descriptions of these valve sets).
2
2
C bus has stopped functioning, this Watchdog
- Auto-zero solenoid valve
X
converter housing (see Figure 3-5).
2
2
C bus.
2
C bus and the relay PCA can
Principles of Operation
2
C bus watch-dog
C bus. Special circuitry
313