Measurement-computing CIO-DAS16/M1/16 Instrukcja Użytkownika Pobierz pdf (Strona 20)

Table 5-5. 82C55 Registers

Configure 82C55 None. No read back on 82C55BASE + 403

Port C OutputPort C InputBASE + 402

Port B OutputPort B InputBASE + 401

Port A OutputPort A Input of 82C55 BASE + 400

WRITE FUNCTIONREAD FUNCTIONADDRESS

The two groups of ports, group A and group B, may be independently programmed in one of several modes. The most

commonly used mode is mode 0, input / output mode. The codes for programming the 82C55 in this mode are shown

in Table 5-6 below.

Table 5-6. 82C55 Configuration Coding

ININININ1559B1111

OUTINININ1549A0111

INOUTININ153991011

OUTOUTININ152980011

ININOUTIN147931101

OUTINOUTIN146920101

INOUTOUTIN145911001

OUTOUTOUTIN144900001

INININOUT1398B1110

OUTININOUT1388A0110

INOUTINOUT137891010

OUTOUTINOUT136880010

ININOUTOUT131831100

OUTINOUTOUT130820100

INOUTOUTOUT129811000

OUTOUTOUTOUT128800000

CLBCUADECHEXD0D1D3D4

NOTE: D7 is always “1”. D6, D5, and D2 are always “0”.

6 CALIBRATION AND TEST

Every board is fully tested and calibrated before leaving the factory. For normal environments a calibration interval of

six months to one year is recommended. If frequent variations in temperature or humidity are common then

recalibrate at least once every three months. It takes less than 30 minutes to calibrate the board.

You will not need an extender card to calibrate theboard but you will need to have the cover off your computer with

the power on, so trim pots can be adjusted during calibration.

The A/D is calibrated by applying a known voltage to an analog input channel and adjusting trim pots for offset and

gain. There are two trim pots requiring adjustment to calibrate the analog input section. The entire procedure is

described in detail in the InstaCal

, calibration routine.

The CIO-DAS16/M1/16 should be calibrated for the range you intend to use it in. When the range is changed, slight

variations in zero and full scale may result. These variations can be measured and removed in software if necessary.

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Measurement-computing CIO-DAS16/M1/16 Instrukcja Użytkownika Strona 20