Keysight E4980AL - DC Isolation Input Signals (Photo-Coupled)

-480 Keysight E4980A/AL User’s Guide
Handler Interface
Electrical Characteristics
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Figure E-7 Output circuit configuration for the control output signals
DC isolation input signals (photo-coupled)
DC isolation input signals include /EXT_TRIG and /KEY_LOCK signals.
1. /EXT_TRIG signal
The /EXT_TRIG signal (pins 12 and 13) is input to the photocoupler LED
(on the cathode side). When the signal rises from LOW to HIGH, the
instrument is triggered. The photocoupler LED (on the anode side) is
driven by either internal pull-up voltage (+5 V,+12 V) or external voltage
(EXT.DCV2).
The trigger input limiting resistor should be set via jumper J6 depending
on the magnitude of the photocoupler anode voltage. For more
information, see
“Setting Up the Handler Interface Board” on page 483.