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4.2 Lab - P O DAO Board for the Deposition Svstem
In automating this equipment, two Lab - PC+ DAQ boards [6] are used The Lab
- PC+ is a low cost multiftanction analog, digital, and timing I/O board for the PC. The
Lab - PC+ contains a 12-bit successive approximation ADC with eight analog inputs,
which can be configured as eight single-ended or four differential channels. The Lab PC+ also has two 12-bit DACs with voltage outputs, 24 lines of TTL-compatible digital
I/O, and six 16-bit counter/timer channels for timing I/O.
The Lab - PC+ contains six jumpers and one DIP switch to configure the PC bus
interface and analog I/O settings. The DIP switch is used to set the base I/O address. Two
jumpers are used as intermpt channel and DMA selectors. The remaining four jumpers
are used to change the analog input and output circuitry. The first PC+ board is
configured as devicel and the second one as device2. For device 1 the Base I/O address
is Hex240 and Hex280 for the other. The DMA channel is 3 for both the devices and the
intermpt line is 5 for both the devices. Channels ACHO through ACH7 are for analog
inputs. The Figure 4.5 shows the operational diagram of Lab-PC+. Table 4.1 shows the
pin configuration of PC+ board.
Computer
— ^
4
Lab-PC+
1—•
DACO
1—•
DACl
^
w
<
^
W
< —
Figure 4.5 Operation of Lab PC+
67
Ports B &C
Analog Input
Signals