Electrical Characteristics Of The Input/Output Signals; Channel Selection Input Signals; External Trigger Input Signals - Keysight E4980A User Manual

Scanner Interface

Electrical Characteristics of the Input/Output Signals

Electrical Characteristics of the Input/Output Signals
The electrical characteristics of the scanner interface I/O signals are described
below.

Channel Selection Input Signals

The /CH0 to /CH7 and /CH_VALID signals are optocoupled to isolate DC
inputs. Each signal is connected to the cathode of an LED in the optocoupler,
which is current driven, requiring 5 mA to 20 mA for proper operation. The
OFF-state voltage (high level) of each signal depends on the pull-up voltage
(EXT. DCV) used. EXT. DCV can be set from 5 V to 15 V. The selector switches
must be set according to the value of EXT. DCV used (Refer to

External Trigger Input Signals

The EXT_TRIG signal is optocoupled to dc isolate the input. This signal is
connected to the cathode of an LED in an optocoupler which is current driven,
requiring 6.3 mA to 15 mA for proper operation. The OFF state voltage (high
level) of each signal depends on the pull-up voltage (EXT. DCV) used. EXT.
DCV can be set from 5 V to 15 V. The bit selector switches must be set
according to the value of EXT. DCV used (Refer to
Table F-9 DC isolate input signal electrical characteristics
Signal Name Input Vol tage
Low
/CH0 to /CH7 0 to 1 V
/CH_VALID
EXT_TRIG 0 to 1 V
Figure F-6
shows a diagram of external trigger input signals.
-494
Input Vol tage (when low) (reference value)
Pull-up Supply Vol tage EXT. DCV
High 5 V
EXT.DCV 9.0 mA
EXT.DCV 11.1 mA
shows a diagram of channel selection input signals, and
Table
Table F-9).
12 V 15 V
12.7 mA 16.2 mA
10.5 mA 13.5 mA
Keysight E4980A/AL User's Guide
F-9).
Figure F-7