Measurement Computing PCI-DIO48H/CTR15 - Manual (Page 5)

1 INTRODUCTION
The PCI-DIO48H/CTR15 is a multifunction, logic level, digital I/O board for
computers that implement the PCI bus. The board offers a powerful combination of
parallel digital I/O and multiple counter/timer functionality.
The board provides 48 bits of parallel digital I/O and fifteen 16-bit counter/timers.
The parallel digital I/O is provided in 24-bit groups based on an 8255, mode 0
emulation. Each group provides an 8-bit port A, an 8-bit port B, and an 8-bit port C
that can be split into two independent 4-bit ports. The 74S244 digital output drivers
have 64 mA sink and 15 mA source capabilities. The 74LS373 input buffers offer the
high standard input impedance of the 74LS series.
On power-up and reset, all I/O bits are set to input mode. Like all members of the
74LS series, unconnected inputs will typically float high. If you are using the board to
control items that must be OFF on reset, you must install pull-down resistors.
Provisions have been made on the board to allow users to easily install SIP resistor
packs in either a pull-up or pull-down configuration.
The board mounts five, 82C54 16-bit down-counter chips. Each 82C54 has three
counter/timers. The user has access to all gate, clock and output signals for all 15
counters in the five 82C54 counter chips. The board also has a 10 MHz
crystal-controlled oscillator that can be connected to one or more counter inputs.
The board is completely plug-and-play. There are no switches or jumpers to set. All
board addresses, interrupt levels, etc. are set by your computer’s plug-and-play
software.
2 INSTALLATION
The PCI-DIO48H/CTR15 boards are easy to install and use. This procedure will help
you quickly and easily setup, install and test your board. We assume you already
know how to open the PC and install expansion boards. If you are unfamiliar or
uncomfortable with board installation, please refer to your computer’s documentation.
2.1 SOFTWARE
The board has no switches or jumpers to set. The simplest way to install your board
and test the installation is to use the InstaCal
TM program provided on the CD (or
floppy disk) supplied with your board.
1