External Instruments

The PXB’s configurable I/O ports can connect with a variety of external devices. When configured for input, an I/O port can accept digital waveform data from an N9020A MXA Signal Analyzer. When configured for output, an I/O port can send digital waveform data to an Agilent E4438C ESG or N5182A MXG vector signal generator for conversion to RF, or to an Agilent N5102A Digital Signal Interface Module for direct digital transmission to user devices under test. The PXB also supports 8960 fading. In this case, the PXB uses bi-directional transmission over a single LVDS I/O port to receive a signal from an Agilent 8960 Wireless Communications Test Set, fade it, and send it back to the 8960 for measurement.

Assigning external devices is the first step after choosing a predefined configuration. Assign an external device by clicking the down-arrow of an external instrument (x) block. From the dialog, you can pick an instrument from your list of already added instruments, or you can add an instrument to the list if a connection has never been established. Note that the drop-down list will only display instruments that are valid for the chosen configuration. You can also view and add instruments through the External Instrument Table.

When adding (or registering) an instrument, you need to give the instrument a unique name. You also need a LAN (TCPIP) or GPIB connection between the PXB and external instruments to communicate setup and control information. You need to specify the type of interface and provide an address for the connected instrument.

The PXB has room for up to four I/O boards. Each I/O board (A, B, C, or D) has two ports; port A1 represents the first port on the first I/O board, A2 is the second port on the first I/O board, and so on. Your list of available I/O ports will reflect the number of I/O boards installed in your PXB. Choose the port you want to use to connect to your assigned instrument. Also choose whether you want to transfer waveforms via digital bus or as analog I/Q. Note that I/O ports assigned to an MXA, 8960, or N5102A Digital Signal Interface Module only transfer digital waveform data via the digital bus (not analog I/Q).  

At any time, you can add instruments or modify existing instrument profiles by clicking the "External Instrument Table” tab.

When you’re finished setting up your external instruments, load your settings to configure the PXB’s internal hardware. Once loaded, you can click an external instrument block to gain remote access to key instrument settings. Notice also that the list on the left of the PXB’s user interface changed from a configuration browser to a settings browser. You can change your instrument settings from the settings browser just as you can by clicking a block. Changes to these instrument settings occur in real time. Clicking "Block Diagram” will return you to the main block diagram view. Note that you can change your external instrument assignments after loading the configuration by clicking the Change Resource Assignments button; however, you will need re-load the configuration to reconfigure the PXB's internal hardware.