Measurement-computing PC104-DIO48 Manual de usuario

PC104-DIO48User’s ManualRevision 4April, 2001

3 CONTROL & DATA REGISTERSWe recommend that you use the Universal Library for all high levelprogramming. The following is basic information on th

The method of programming required to set/read bits from bytes isbeyond the scope of this manual. It is covered in most Introduction ToProgramming bo

Bit set/reset and bit read functions require that unwanted bits be maskedout of reads and ORed into writes.PORT C DATA BASE ADDRESS + 2 (1st 82C55)BA

The 82C55 can be programmed to operate in Input/ Output (mode 0),Strobed Input/ Output (mode 1) or Bi-Directional Bus (mode 2).Information on programm

Table 2-3. Mode 0 - Port I/O Select CodesININININ1559B1111OUTINININ1549A0111INOUTININ153991011OUTOUTININ152980011ININOUTIN147931101OUTINOUTIN146920101

4 SPECIFICATIONSPower consumption+5V Operating 130 mA typical, 200 mA maxDigital Input / OutputDigital Type 82C55Configuration 4 ports of 8, 4 ports

5 ELECTRONICS AND INTERFACINGThis brief introduction to the electronics most often needed by digitalI/O board users covers the following subjects:Pull

The concept of voltage level of an 82C55 in input mode is meaningless.Do not connect a volt meter to the floating input of an 82C55. It willshow you

The board is equipped with positions for pull-up/down resistors SingleInline Packages (SIPs). The positions are marked RN1 through RN6 andare located

5.3 VOLTAGE DIVIDERSIf you wish to measure a signal which varies over a range greater thanthe input range of a digital input, a proper voltage divider

Your new Measurement Computing product comes with a fantastic extra — Management committed to your satisfaction! Thank you for choosing a Measurement

Dropping the voltage proportionally is called attenuation. The formulafor attenuation is:For a given attenuation, pick a handy resisitorand call it R

5.4 LOW PASS FILTERS DE-BOUNCE INPUTSA low pass filter is placed on the signal wires between a signal and anDIO board. It attenuates frequencies grea

A simple low-pass filter may be constructed from one resistor (R) andone capacitor (C) (Figure 5-3). The cut-off frequency is determinedaccording to

EC Declaration of ConformityWe, Measurement Computing Corporation, declare under sole responsibility that theproduct:DescriptionPart Number48-Bit Digi

Measurement Computing Corporation 10 Commerce Way Suite 1008 Norton, Massachusetts 02766 (508) 946-5100 Fax: (508) 946-9500 E-mail: [email protected]

Table of Contents175.4 LOW PASS FILTERS DE-BOUNCE INPUTS...155.3 VOLTAGE DIVIDERS...145.2 TTL TO SOLID S

This page is blank.

1 SOFTWARE INSTALLATIONThe board has switches and jumpers to set before installing the board inyour computer. By far the simplest way to configure you

The actual address is constructed by calculating the HEX or decimalnumber Base Address Select Switches which corresponds to the baseaddress bits th

2.2 INSTALLING THE BOARD1. Turn the power off.2. Push the board firmly down into the expansion bus connector. If it isnot seated fully it may fail to

Figure 2-2. PC104-DIO48 Board Layout and Pin 1 LocationIMPORTANT NOTE: The PC104-DIO48 uses two 82C55 digitalchips for digital I/O. The 82C55 digit

In other words, if you connect bit A0 and not bit A1, do not be surprisedif A1 stays low, stays high or tracks A0. It is unconnected and so, is notspe