Agilent Technologies E3632A - Manual (Page 53)

Chapter 3 Front-Panel Operation
Disabling the Output Using an External Relay
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3
Disabling the Output Using an External Relay
When the output of the E3632A 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 0.
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”.
N o t e
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.
N o t e
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.
Knob Locking
The knob locking function can be used to disable the knob, thereby preventing
any unwanted changes during an experiment, or when you leave the power
supply unattended. To disable the knob, press the resolution selection key until
the blinking digit disappears.
Notice that the knob and front panel keys are disabled when in the remote
interface mode.