Advantech PCL-818 Series Manual do Utilizador descarregar pdf (Página 33)

25 Chapter 3

Table 3-3: Jumper JP11 Settings

When you set JPI1 to INT, the D/A converter takes its reference voltage

input from the card's on-board reference. Jumper JP10 selects either -5 V

or -10 V on-board reference voltage. With JP11 set to INT the D/A chan-

nel has an output range of 0 to +5 V or 0 to +10 V, respectively.

When you set JP11 to EXT, the D/A converter takes its reference voltage

input from pin 31 of connector CN3.You can apply any voltage between -

10 V and +10 V to this pin to function as the external reference. The ref-

erence input can be either DC or AC (<100 KHz).

When you use an external reference with voltage Vref you can program

the D/A channel to output from 0 V to -Vref, you can also use the D/A

converter as a programmable attenuator. The attenuation factor between

reference input and analog output is:

Attenuation factor = G / 4095

Where G is a value you write to the D/A registers between 0 and 4095.

For example, if you set G to 2048, then the attenuation factor is 0.5. A

sine wave of 10 V amplitude applied to the reference input will generate a

sine wave of 5 V amplitude on the analog output.

Jumpers Function Description

JP11 External

Internal (default)

1 2 ... 28 29 30 31 32 33 34 35 36 37 38 ... 73 74

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