National Instruments 653 Series User Manual page 98

Connecting Signals with
Accessories
Control Signals
Signal Name
REQ<1..2>
ACK<1..2>
or
STARTTRIG<1..2>
STOPTRIG<1..2>
PCLK<1..2>
© National Instruments Corporation
This appendix describes how to connect signals to your NI 653X. Use the
first part of the appendix to acquaint yourself with the device control
signals. Then go to appropriate pinout diagrams (68- or 50-pin), which
display the layout of pin locations.
Use the four control signals to regulate/control the timing of your data
transfer when using the handshaking and pattern I/O modes. The direction
and function of each signal varies, depending on the mode of operation,
as shown in Table C-1.
Table C-1. Control Signals for Handshaking I/O and Pattern I/O
Handshaking I/O
Direction Function
Input Request—Indicates
that the peripheral
device is ready
Output Acknowledge—
Indicates the
NI 653X is ready
N/A
Input or Peripheral clock
Output
Direction
Input or
Output
Input
N/A Input
N/A
C-1
C
Pattern I/O
Function
Request—
Clocks the data transfer
Start trigger
Stop trigger
N/A
NI 653X User Manual