Features and Functions
3
Keysight 34980A Mainframe User’s Guide
171
Scanning With External Instruments
If your application doesn’t require the built-in measurement capabilities of the
34980A, you can order the mainframe without the internal DMM. In this
configuration, you can use the system for signal routing or control applications. If
you install a multiplexer plug-in module in the mainframe, you can use the system
for scanning with an external instrument. You can connect an external instrument
such as a DMM to the multiplexer’s COM terminals (see below) or you can
connect to the 34980A’s analog buses.
The figure on the following page shows the external connections required to
synchronize the scan sequence between the 34980A and an external instrument.
The 34980A must notify the external instrument when a relay is closed and fully
settled (including channel delay). The 34980A outputs a
Channel Closed
pulse
from pin 5 on the rear-panel
Ext Trig
connector. In response, the external
instrument must notify the 34980A when it has finished its measurement and is
ready to advance to the next channel in the scan list. The 34980A accepts a
Channel Advance
pulse on the
Chan Adv
input line (pin 6).
Input
Channels
Common Terminals
(COM)
H
L
External DMM