NI Digital Waveform Generator/Analyzer Guide
24
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NI 656
x
Front Panels and Connectors
The NI 656
x
front panels contain four connectors—three SMB jacks
(CLK IN, PFI 0, and CLK OUT) and one 73-pin 12x Infiniband connector
(DIGITAL DATA & CONTROL, or DDC).
Figure 13 shows the NI 6561 front panels and pinout, which are identical to
those of the NI 6562. Signals marked with an asterisk represent the
complementary terminal for the differential signal of the same name. The
DDC signals are described in Table 3. The SMB connectors are the same as
those described in Table 4, and the LEDs are the same as those described in
Tables 5 and 6.
Table 2.
NI 655
x
DDC Connector Pins
Pins
Signal Name
Signal Type
Signal Description
33
DDC CLKOUT
Control
Output terminal for the
exported Sample clock.
67
STROBE
Control
Terminal for the external
Sample clock source which
can be used for dynamic
acquisition.
13, 15, 17, 19,
21, 23, 25, 27,
29, 31, 47, 49,
51, 53, 55, 57,
59, 61, 63, 65
DIO <0..19>
Data
Bidirectional digital I/O data
channels 0 through 19.
26, 30, 64
PFI <1..3>
Control
Input terminals to the
NI 655
x
for external triggers,
or output terminals from the
NI 655
x
for events.
2, 4, 6, 10, 12,
14, 16, 18, 20,
22, 24, 28, 32,
34, 36, 38, 40,
42, 44, 46, 48,
50, 54, 56, 58,
62, 66
GND
Ground
Ground reference for signals.
1, 3, 5, 7, 8, 9,
11, 35, 37, 39,
41, 43, 45, 52, 60
RESERVED
N/A
These terminals are reserved
for future use. Do not
connect to these pins.