User`s guide

Chapter 5 Service
To Disconnect the Output Using an External Relay
103
5
To Disconnect 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 connector 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 below for more information.
Note 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.
Installation Procedure
The assembly drawings are located in chapter 6, ‘‘Component Drawings’’.
1 Remove the front and rear bumpers and take off the cover .
2 Install JP3
[1]
and JP4 located adjacent to the connector P5 (the JP3 and JP4 are
outlined with a circle in the component locator diagram on page 111).
A bare wire may be used.
3 Reassemble the power supply.
[1]For serial MY53xx6xxx, install JP001 and JP002 located adjacent to the
connector CN001 (the JP001 and JP002 are outlined with a circle in the
component locator diagram on
page 113).