Keysight E3633A, User Manual

Page: 72 / 205

3 Front-Panel Operation
72 Keysight E3633A and E3634A User’s Guide
Disabling the Output Using an External Relay
When the output of the power supply is turned off, it is implemented by setting
the output to 0 volts and 0.02 amps. This gives a zero output voltage without
actually disconnecting the output. To disconnect the output an external relay
must be connected between the output and the load. A TTL signal of either low
true or high true is provided to control an external relay. This signal can only be
controlled with the remote command
OUTPut:RELay {OFF|ON}
. The TTL output
is available on the RS-232 connection pin 1 and pin 9.
When the
OUTPut:RELay
state is “ON”, the TTL output of pin 1 is high (4.5 V) and
pin 9 is low (0.5 V). The levels are reversed when the
OUTPut:RELay
state is
“OFF”.
NOTE
– TTL output of pin 1 or pin 9 of the RS-232 connector is available only after
installing two jumpers inside the power supply. See the Service Guide for
more information.
– Do not use the RS-232 interface if you have configured the power supply to
output relay control signals. Internal components on the RS-232 circuitry
may be damaged.