Keithley 7037, Инструкция по эксплуатации

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3
Digital I/O Configuration
3-1
Introduction
This section covers the basic digital input and output config
urations for the Model 7037. Connection information for
these configurations is provided in Section 4 of this manual,
while operation (front panel and IEEE-488 bus) is explained
in Section 5.
Digital outputs
Output channels are user configurable for negative (low) or
positive (high) true logic. That is, the output can be high or
low when the channel is turned on (closed) depending upon
user configuration. Conversely, the output can be high or low
when the channel is turned off (open). Refer to Section 4 to
configure the logic to your requirement
Controlling pull-up devices
Typically, the digital outputs are used to provide drive for rel-
atively high current devices such as solenoids, relays, and
small motors. The configurations for these applications are
shown in Figure 3-1. Figure 3-1 allows you to use an external
voltage source (V) for devices that require a higher voltage
(42V maximum). An internal jumper is used to select the
internal pull-up voltage. At the factory, the internal 5V
source is selected.
Each output channel uses a fly-back diode for protection
when switching an inductive device, such as a solenoid coil.
This diode diverts the potentially damaging fly-back voltage
away from the driver.
Figure 3-1
Output configu ation for pull-up devices
Driver
Jumper
V
V
EXT
Solenoid or
relay coil
7037
5V
NOTE: Output configuration uses
an external voltage source
(42V maximum).
10k
Ω
(42V maximum)