Measurement Computing CIO-DAS08-AOH - Manual (Page 12)

NOTE: When using the CIO-DAS08-PGx with the CIO-EXP16 or CIO-EXP32, the optional SIP resistor must be
installed. The CIO-EXP16 and CIO-EXP32 (and MetraByte EXP16) were designed to interface to a single-ended
input. Failure to install the SIP resistor when the board is used with these expansion boards will result in floating,
unstable readings.
Special instructions and solder are packaged with the SIP resistor. Follow the installation instructions
carefully and use the solder provided. Use of any other solder, or failure to follow instructions can result in
a degradation of the analog input's accuracy and may require out-of-warranty repair.
5.3 DIGITAL OUTPUTS & INPUTS OP0-2 & IP0-3
The digital outputs and inputs located on the main, or analog connector, may best be reserved for use as CIO-EXP mux
controls or trigger inputs. General digital interfacing should be done on the rear 24-bit digital connector.
The digital inputs/outputs on the CIO-DAS08-AOx are at TTL level. TTL is an electronics industry term, short for Transistor
Transistor Logic, with describes a standard for digital signals. It is a common misconception that TTL signals are always 0V
for low and +5V for high. Although the low signal is reliably close to 0V, the high signal may be anywhere from 2.4V to 5V,
and be within the TTL specification.
5.4 DIGITAL I/O CONNECTOR
The 24 bits of digital I/O at the rear of the board are brought to a 40-pin header connector. You can assemble your own cable
or purchase a BP40-37 which translates the 40-pin header into a 37-pin, D-type connector with mounting bracket.
Figure 4-2 is the schematic for the BP40-37.
After connection to a BP40-37, the signals at the 37-pin D connector are exactly the same as a CIO-DIO24 or MetraByte
PIO12 standard.
Figure 4-3 has the pin assignments at the 37-pin connector.
Figure 4-2. BP-37 Cable Schematic Figure 4-3. Pin Assignments on D-37 End of BP40-37
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