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The circuitry consists of Plug and Play address decoders, data buffers,

I/O channel interface timing control circuitry, and interrupt control

circuitry. The circuitry monitors address lines SA4 through SA15 to

generate the board enable signal, and uses lines SA0 through SA3 plus

timing signals to generate the onboard register select signals and

read/write signals. The data buffers control the direction of data transfer

on the bidirectional data lines based on whether the transfer is a read or

write operation.

The interrupt control circuitry routes any enabled interrupts to the

selected interrupt request line. The PC-LPM-16PnP has six interrupt

request lines available: IRQ3, IRQ4, IRQ5, IRQ6, IRQ7, and IRQ9.

The PC-LPM-16PnP generates interrupts in three different situations:

• When an A/D conversion generates data that can be read from FIFO

• When an active low-level signal is detected on the EXTINT* line

• When a rising-edge signal is detected on counter 2 output

The PC-LPM-16PnP individually enables and clears each one of these

interrupts. For more detailed information on generating interrupts

externally, see the EXTINTEN bit of the Command Register 1

description in Appendix D, Register-Level Programming.

Analog Input and Data Acquisition Circuitry

The PC-LPM-16PnP has 16 channels of analog input with 12-bit

A/D conversion. Using the timing circuitry, the PC-LPM-16PnP can

also automatically time multiple A/D conversions. Figure 3-3 shows a

block diagram of the analog input and data acquisition circuitry.

Hardware Installation

You can install the PC-LPM-16PnP in any available expansion slot in

your computer. The following are general installation instructions, but

consult your computer user manual or technical reference manual for

specific instructions and warnings.

1. Turn off and unplug your computer.

2. Remove the top cover or access port to the I/O channel.

3. Remove the expansion slot cover on the back panel of the computer.

4. Insert the PC-LPM-16PnP board into any 8-bit or 16-bit slot. It may

be a tight fit, but do not force the board into place.

5. Screw the mounting bracket of the PC-LPM-16PnP board to the

back panel rail of the computer.

6. Replace the cover.

7. Plug in and turn on your computer.

The PC-LPM-16PnP is installed.

Software Installation

If you are using NI-DAQ, refer to your NI-DAQ release notes to install

your driver software. Find the installation section for your operating

system and follow the instructions given there.

If you are using LabVIEW, refer to your LabVIEW release notes to

install your application software. After you have installed LabVIEW,

refer to the NI-DAQ release notes and follow the instructions given

there for your operating system and LabVIEW.

If you are using LabWindows/CVI, refer to your LabWindows/CVI

release notes to install your application software. After you have

installed LabWindows/CVI, refer to the NI-DAQ release notes and

follow the instructions given there for your operating system and

LabWindows/CVI.

If you are a register-level programmer, refer to Appendix D, Register-

Level Programming, for software configuration information.

Register-Level Programming

The final option for programming any National Instruments DAQ

hardware is to write register-level software. Writing register-level

programming software can be very time-consuming and inefficient and

is not recommended for most users.

Even if you are an experienced register-level programmer, consider

using NI-DAQ, LabVIEW, or LabWindows/CVI to program your

National Instruments DAQ hardware. Using the NI-DAQ, LabVIEW, or

LabWindows/CVI software is as easy and as flexible as register-level

programming and can save weeks of development time.

Optional Equipment

National Instruments offers a variety of products to use with your

PC-LPM-16/PnP board, including cables, connector blocks, and other

accessories, as follows:

• Cables and cable assemblies, shielded and ribbon

• Connector blocks, shielded and unshielded with 50-pin screw terminals

• SCXI modules and accessories for isolating, amplifying, exciting,

and multiplexing signals for relays and analog output. With SCXI

you can condition and acquire up to 3,072 channels.

• Low channel-count signal conditioning modules, boards, and

accessories, including conditioning for strain gauges and RTDs,

simultaneous sample-and-hold circuitry, and relays

For more specific information about these products, refer to your

National Instruments catalogue or call the office nearest you.

About the PC-LPM-16/PnP

The PC-LPM-16/PnP is a low-cost, low-power analog input, digital,

and timing I/O board for the PC. The board contains a 12-bit,

successive-approximation, self-calibrating ADC with 16 analog inputs,

8 lines of TTL-compatible digital input, and 8 lines of digital output.

The PC-LPM-16/PnP also contains two 16-bit counter/timer channels

for timing I/O.

The low cost of a PC-LPM-16/PnP-based system makes it ideal for

laboratory work in industrial and academic environments. The board’s

low power consumption and small size make the PC-LPM-16/PnP

especially suitable for laptop computers. The multichannel analog input

is useful in signal analysis and data logging. The 12-bit ADC is useful

in high-resolution applications such as chromatography, temperature

measurement, and DC voltage measurement. You can use the 16 TTLcompatible

digital I/O lines for switching external devices such as

transistors and solid-state relays, for reading the status of external

digital logic, and for generating interrupts. You can use the

counter/timers to synchronize events, generate pulses, and measure

frequency and time. The PC-LPM-16/PnP, used in conjunction with

your computer, is a versatile, cost-effective platform for laboratory test,

measurement, and control.