Dräger Medical Zeus, Technical Documentation Manual

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Function Description Zeus
Figure 12 Block diagram of the DAGMAR PCB
The operating voltage for the sensors (12 V) and the processor system (5 V)
is derived from the supply voltage. The input voltage is monitored by the pro-
cessor system.
The supply pressure sensors operate in a range from 0 to 4 bar absolute,
delivering an output voltage of 0 to 5 V. The processor system reads in the
output voltages by way of an A/D converter and evaluates them.
The DAGMAR valve block is controlled by a power driver. In the event of an
error the voltage to the power driver for the carrier gas can be cut by means
of a “dead man's signal” on the system bus. For safety reasons, the signal on
the system bus is electrically isolated by an optocoupler.
The processor system has a serial interface which is also configurable to TTL
level.
The signals on the CAN bus, too, are electrically isolated from the rest of the
system by optocoupler.
The LEDs and jumpers on the PCB are currently only used by Development,
and are irrelevant to Service.