Chapter 4 Signal Connections
© National Instruments Corporation 4-5 DIO 6533 User Manual
40 CPULL Bias
Selection Control pull-up/pull-down selection—This input
signal selects whether the 6533 device pulls the
timing and handshaking control lines (REQ,
ACK, PCLK, and STOPTRIG) up or down when
undriven. If you connect CPULL to +5 V, the
6533 device pulls the control lines up. If you
connect CPULL to GND or leave CPULL
unconnected, the 6533 device pulls the control
lines down.
38 DPULL Bias
Selection Data pull-up/pull-down selection—This input
signal selects whether the 6533 device pulls the
data lines (DIOA, DIOB, DIOC, and DIOD) up
or down when undriven. If you connect DPULL
to +5 V, the 6533 device pulls the data lines up.
If you connect DPULL to GND or leave DPULL
unconnected, the 6533 device pulls the data lines
down.
1+5 V Power 5 Volts, output—This line provides a maximum
of 1 A of power, regulated by a n onboard fuse
that can automatically reset itself after current
returns to normal.
11, 14, 18,
20, 24, 27,
30, 33, 36–
37, 41–42,
46, 49–50,
55, 59, 62,
65, 68
GND Power Ground—These lines are the ground reference
for all other signals.
19, 35, 43,
56 RGND Power Reserved ground—These lines offer additional
ground pins that vary in connection from cable to
cable. With an R6868 ribbon cable, you can use
these lines as additional ground references. With
an SH68-68-D1, however, these signals are not
connected.
Table 4-1.
Signal Descriptions (Continued)
Pins Signal Name Signal Type Description