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Led drive – Agilent Technologies L4400 User Manual

Page 163

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L4445A Microwave Switch/Attenuator Driver

7

L4400 User’s Guide

151

LED Drive

The distribution boards contain a ribbon cable header you can use to
connect LEDs to provide a visual indication of switch state. These lines
reflect the state of their corresponding channel’s position indicator. Some
systems use LEDs as a graphical indicator of switch positions.

Use the

ROUTe:RMODule:BANK:LED:DRIVe:LEVel

command to set the drive

current for the LEDs. You do not need to provide an external current
limiting resistor. This command uses special channel addressing as
described in

“Remote Module Identifiers”

on page 145.

Once the drive current is set, enable the LED drives using the

ROUTe:RMODule:BANK:LED:DRIVe:ENABle

command. This command uses

special channel addressing as described in

“Remote Module Identifiers”

on

page 145.

The LEDs obtain their power from the remote module power supply. If
the

ROUTe:RMODule:DRIVe:SOURce OFF

command has been sent,

the LEDs will not operate.

Simplified connections for the position indicators are shown in the
diagrams beginning on

page 184

.

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