Measurement Computing CIO-DO48H - Manual (Page 9)

4 HARDWARE INSTALLATION
4.1 INSTALL BOARD
1. Turn the power off.
2. Remove the cover of your computer. Be careful not to dislodge any of the cables
installed on the boards in your computer as you slide the cover off.
3. Locate an empty expansion slot in your computer.
4. Push the board firmly down into the expansion bus connector. If it is not seated
fully it may fail to work and could short circuit the PC bus power onto a PC bus
signal. This could damage the motherboard in your PC as well as the CIO-DOxxH.
4.2 CABLING TO THE CONNECTOR
The connector(s) are accessible through the PC/AT expansion bracket. The
connector is a standard 50 pin header connector. A cable with mating connectors
(C50FF-#) can be purchased from Mesurement Computing Corp.
Those familiar with the CIO-DIO##H boards will find the signal levels and pin
assignments are identical with those on the CIO-DOxxH.
4.3 SIGNAL CONNECTION
The CIO-DOxxH signals are buffered (high output drive) STTL. STTL is an
electronics industry term, short for Schotky Transistor Transistor Logic, which
describes a standard for digital signals which are either at 0V or 5V.
Under normal operating conditions, the voltages on the output pins range from near
0 volts for the low state to near 5.0 volts for the high state.
CAUTION
Voltages and currents associated with external devices can range from less than a
hundred mA at a few volts for a small flash light bulb to 50 Amps at 220 volts for a
large electric range. Attempting to connect either of these devices directly to the
CIO-DO48 would destroy the output buffer chip.
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