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11-4
Digital I/O, Analog Outputs, and External Feedback
CAUTION
Do not 33V maximum voltage on pin 5 of the digital I/O port, and
do not use any output line to sink >500mA. Exceeding these limits may
cause damage to the instrument that is not covered by the warranty.
An externally powered relay connected to the digital output port is shown in Figure 11-3.
Other externally powered devices can be similarly connected by replacing the relay with the
device. When the output line is set LO (0V), the output transistor sinks current through the exter-
nal device. In the HI state, the output transistor is off (transistor switch open). This interrupts
current flow through the external device.
+5V
1k
Ω
Pull Up Resistor
Pin 9 - Digital Ground
Pin 1 - Digital Output #1
Pin 5 - External Voltage Flyback Connection
Digital Output #1
Flyback Diode
To other three
digital outputs
Relay
Coil
Relay
Coil
(+)
(+)
(-)
(-)
External Power
(+5V to +33V)
External Power
(+5V to +33V)
Model 6514
Transistor Switch
Flyback
Diode
Equivalent Circuit
Figure 11-3
Controlling externally
powered relays
Summary of Contents for 6514
Page 203: ...14 CommonCommands...
Page 207: ...15 SCPISignalOriented MeasurementCommands...
Page 235: ...18 PerformanceVerification...
Page 254: ...19 Calibration...
Page 274: ...20 RoutineMaintenance...
Page 278: ...A Specifications...
Page 282: ...B StatusandErrorMessages...
Page 288: ...C GeneralMeasurement Considerations...
Page 294: ...D DDCEmulationCommands...
Page 299: ...E ExamplePrograms...
Page 306: ...F IEEE 488BusOverview...
Page 320: ...G IEEE 488andSCPI ConformanceInformation...
Page 324: ...H CalibrationOptions...