Transmission Line Effects - National Instruments NI Vision CVS-1450 Series User Manual

Chapter 4 Digital I/O Functionality

Transmission Line Effects

NI CVS-1450 Series User Manual
Vcc
CVS-1450 device
Figure 4-7. Example of Using an External Flyback Diode for Inductive Loads
Transmission line effects can degrade the signals on the I/O cables and
cause instability. To minimize transmission line effects, use twisted-pair
wires with a characteristic impedance of 118 Ω to connect external signals
to the 44-pin I/O DSUB connector. Use a 75 Ω coaxial cable, such as
RG-179, to connect to the SMB connectors.
Figure 4-8 shows connections to the 44-pin DSUB connector and the
TRIG 0 SMB connector that minimize transmission line effects.
Digital
Output
4-14
Viso
Load
Ciso
External
Flyback
Diode for
Inductive Loads
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