User manual
Model 6220/6221 User’s Manual Output Connections 2-5
Return to Section 2 topics
Output configurations
There are four configurations that can be used for current source output:
• Triax inner shield is connected to Output Low, which is connected to Earth 
Ground (see Figure 2-4A).
• Triax inner shield is connected to Cable Guard and Output Low is con-
nected to Earth Ground (see Figure 2-5A).
• Triax inner shield is connected to Output Low, which is disconnected from 
Earth Ground (Floating) (see Figure 2-4B). This is the default setting.
• Triax inner shield is connected to Cable Guard. Output Low is accessed at 
the LO banana jack and is disconnected from Earth Ground (Floating) (see 
Figure 2-5B).
Using the Model 622x with the triax inner shield connected to Output Low makes it 
compatible with the Keithley Model 220 current source.
WARNING To prevent electric shock and/or damage to the Model 622x, DO 
NOT exceed the maximum (Max) voltage levels indicated in 
Figure 2-4 and Figure 2-5.
CAUTION To prevent damage to internal fuses of the Model 622x, current 
from output low to earth ground must be limited to 1A. Use a 
fuse or other current limiting device in the external test circuit.
One internal fuse is located between the Triax Output Low and 
banana jack LO. The other internal fuse is located between 
Triax Output Low and earth ground.
Figure 2-4
Output configurations – triax inner shield connected to Output Low
1) Boot color for alligator
clip if using supplied
triax cable.
2) Frequency Variable
Resistor (FVR). See
Figure 2-1.
A) Triax Output Low setting: Earth Ground B) Triax Output Low setting: Floating
OUTPUT
FVR
Chassis
Earth
Ground
105V
Max
250V
Max
Output High
(red)
Output Low
(black)
Earth Ground
(green)
622x
OUTPUT
FVR
Chassis
Earth
Ground
105V
Max
Output High
(red)
Output Low
(black)
Earth Ground
(green)
622x
1
1
1
1
1
1
2
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