Control external Generator in Fast Sweep Mode

Question

How to connect the SFM100A as an external generator for the ZVA/ZVB in Fast Sweep mode.

Answer

The R&S SMF100A microwave generator can work together with an ZVA/ZVB network analyzer in the Fast Sweep

mode. If Fast Sweep is activated, the analyzer compiles a list of the stimulus values (frequencies and powers) in all channels and transfers it to the generator using GPIB or LAN. The list is automatically updated and retransferred

whenever the channel settings are changed. The analyzer uses trigger handshake to control the generator's List mode. The Fast Sweep mode is useful in one channel only. Interchange between channels requires a new setup of the list,

which decreases speed.

If Fast Sweep is disabled, each measurement point is transferred independently via LAN or GPIB. The data transfer decreases the measurement speed.

A VISA driver on the network analyzer is necessary. If the Fast Sweep mode is used in conjunction with the external generator, it increases the measurement speed many times.

Important: It is very important to select "Custom" during VISA library installation. Check that VISA installation is

really enabled because the VISA driver is not installed by default.

To run the SMF100A - ZVA/ZVB in Fast Sweep mode, you need a trigger connection in addition to the remote interface (GPIB or LAN). It is necessary to connect the ZVA/ZVB’s "User Port" (25-pin D-Sub female) and the SMF100A's "Ext Gen Trigger" and "Ext Gen Blank" BNC connectors. The wiring is shown in the table below.

25-pin D-Sub(male) - Generator (BNC)

--------------------------------

Pin 21 - Ext Gen Trigger

Pin 22 - Ext Gen Blank

Pin 23 - GND

Check "Fast Scan" in the ZVA/ZVB external generator setup.