National Instruments NI CVS-1450 Series User Manual

Page of 91
Chapter 4
Digital I/O Functionality
© National Instruments Corporation
4-15
Figure 4-8.  Example Connections
When connecting to TTL inputs on the CVS-1450 device, match the output 
impedance of the transmitting device to the characteristic impedance of the 
cable. For example, if the cable characteristic impedance is 118 
Ω, make 
R
s
 equal to 118 
Ω, as shown in Figure 4-8.
Typical System Setup
Digital I/O configuration varies depending on the number of cameras your 
system setup requires. You can access the digital I/O through the 44-pin 
DSUB connector or through the three SMB connectors.
The digital I/O capabilities of the SMB connectors on the CVS-1450 device 
are ideal for typical single-camera applications. The SMB connectors are 
labeled TRIG 0TRIG 1, and TRIG 2.
TTL OUT(0)
Receiving
Equipment
TTL IN(0)
118
 Ω
44-Pin
DSUB
3
2
16
17
62 k
Ω
Transmitting
Equipment
R
S
TRIG 1
75
 Ω
TRIG 1
SMB
RG-179 
Coaxial Cable
+5 V
CVS-1450 device
Receiving
Equipment