Measurement Computing PPIO-DIO24H - Manual (Page 6)

3 HARDWARE INSTALLATION
The PPIO-DIO24H is easy to install. There are no switches to set or jumpers to place.
Simply plug it in to your personal computer's parallel printer port, connect field
signals to the I/O connector, and begin switching or monitoring discrete I/O devices.
The PPIO-DIO24H is a digital input and output board. The board uses a set of
registers which emulate an 82C55 in mode 0. The PPIO-DIO24H is compatible with
Measurement Computing’s CIO-DIO24 connector. Since the PPIO-DIO24H uses the
parallel printer port and does not plug into the PC's bus, there is no I/O register-
compatibility with the CIO-DIO24H.
The PPIO-DIO24H provides High Drive inputs and outputs. The DIO24H can sink
about 60 mA with output low. This is more than enough to switch on an LED, a solid
state relay or many types of mechanical relays.
The PPIO-DIO24H is 100% compatible with the 82C55, mode 0. Software written
for any 82C55 based digital I/O board that implements simple I/O using mode 0 will
work with the PPIO-DIO24H after the register addressing has been modified to suit
the layout of the PC's parallel printer port.
3.1 INSTALLING THE PPIO-DIO24H
1. Turn the PC power off.
2. Remove the cover of your computer. Please be careful not to dislodge any of the
cables installed on the boards in your computer as you slide the cover off.
3. Plug the 25-pin cable into the PC's parallel printer port 1, 2, 3 or 4 (also known as
LPT1, LPT1, LPT3 & LPT4; LPT1 and PRN: are the same).
4. Locate an unused accessory power connector in your computer. These are white
plastic, four pin connectors which carry power from your computer's power supply
to disk drives. There should be a few spare connectors.
If there are no spare power connectors, a Y cable (C-PCPOWER-Y) can be
purchased from Measurement Computing to provide a power connection to your
PPIO board.
5. Connect the PPIO Power cable power cable to the PC's accessory power connector.
One end of the PPIO Power Cable plugs into the PC's accessory power connector
and the other is attached to the PPIO-DIO24H.
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