
©
National Instruments Corporation
C-1
C
Connecting Signals with
Accessories
This appendix describes how to connect signals to your 653
X
device. 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.
Control Signals
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
Signal Name
Handshaking I/O
Pattern I/O
Direction
Function
Direction
Function
REQ<1..2>
Input
Request—Indicates
that the peripheral
device is ready
Input or
Output
Request—
Clocks the data transfer
ACK<1..2>
or
STARTTRIG<1..2>
Output
Acknowledge—
Indicates the 653
X
device is ready
Input
Start trigger
STOPTRIG<1..2>
N/A
N/A
Input
Stop trigger
PCLK<1..2>
Input or
Output
Peripheral clock
N/A
N/A