Keithley 6220 Reference Manual page 261

Model 6220/6221 Reference Manual
CAUTION
An externally powered relay connected to the digital output port is shown in
Figure
replacing the relay with the device. When the output line is set LO (0V), the output
transistor sinks current through the external device. In the HI state, the output
transistor is off (transistor switch open). This interrupts current flow through the
external device.
Figure 9-4
Controlling externally powered relays
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com
Do not exceed +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.
9-4. Other externally powered devices can be similarly connected by
Model 622x
W
Return to
Limit Test and Digital I/O
Equivalent Circuit
Section 9 topics
9-7