National Instruments DIO 6533 사용자 설명서
Chapter 4
Signal Connections
DIO 6533 User Manual
4-6
© National Instruments Corporation
Signal Characteristics
Following is a list of signal characteristics. Characteristics are for all
signals, unless otherwise noted. For signal characteristics not given in
this section, see Appendix A,
signals, unless otherwise noted. For signal characteristics not given in
this section, see Appendix A,
• Drive current—After being enabled, all lines that can be configured
for output sink at least 24 mA at 0.4 V, and source at least 24 mA
at 2.4 V.
at 2.4 V.
♦
DAQCard-6533—Your PCMCIA socket may not provide
sufficient power to drive all outputs at 24 mA.
sufficient power to drive all outputs at 24 mA.
• Ground reference—All signals are referenced to the GND lines.
• Initial state—At power up, all control and data lines begin at high
impedance. With no load attached, the voltage levels of the lines
are controlled by the pull-up or pull-down resistors.
are controlled by the pull-up or pull-down resistors.
• Pull-up/pull-down
• Control lines—All timing control lines have 2.2 k
Ω
pull-up or
pull-down resistors, controlled by the CPULL line.
• Data lines—All timing data lines have 100 k
Ω
pull-up or
pull-down resistors, controlled by the DPULL line.
• Bias-selection lines—The CPULL and DPULL lines, which
select the bias of the control and data lines, are themselves
biased low with 20 k
biased low with 20 k
Ω
pull-down resistors. The default bias of
all lines, therefore, is pulled down.
• Polarity
• Data signals—Active high. A 1 corresponds to a high voltage,
and a 0 corresponds to a low voltage.
• Control signals—Depending on the operating mode and
handshaking protocol you select, control signals can be active
high or active low.
high or active low.