Agilent Technologies N6751A User Manual page 163

Bi-directional Digital I/O
Digital Input Only
Series N6700 User's Guide
When the Digital Control pins are configured for bi-directional digital
I/O, the pins function as a bi-directional input/outputs, the state of
which can be controlled and read at all times. The ground reference
for the I/O pin is Signal Common on pin 8. DIGital:OUTPut:DATA
sets the state of the pins and DIGital:OUTPut:DATA? reads the state
of the pins according to the following bit assignments:
Pin 1
Bit Value 0
The input/output pin can be used to control both relay circuits as
well as digital interface circuits. The following figure illustrates
typical relay circuits as well as digital interface circuit connections
using the digital I/O functions.
16.5 V Max.
1 2 3 4 5 6 7
I
Relay driver
Ports 0, 1, 2.
(contains internal
clamp diodes for
inductive flyback)
A) Relay Circuits
For a complete description of the electrical characteristics of the
digital I/O port, see Appendix A.
When an I/O pin is configured for Digital Input only, the pin
functions as a digital input pin. The ground reference for the I/O pin
is Signal Common on pin 8.
The pin status reflects the true condition of the external signal that is
applied to the pin. The pin state is not affected by the value of the
digital output word.
Using the Digital Port Appendix C
2 3 4
1 2 3
1 2 3 4 5
Coil
Current
0.1 A
Max.
Digital Output
1 2 3 4 5
Digital Input
Ports 0, 1, 2
B) Digital Interface Circuits
5 6 7
4 5 6
6 7
I
Ports 0, 1, 2
6 7
I
TTL, AS, CMOS, HC
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