HP FET MULTIPLEXER E1351A/53A manual Commands for Scanning Switchbox Channels

Chapter 4

Understanding the HP E1351A/53A FET Multiplexer Modules

Using This Chapter

This chapter explains techniques to scan the channels of 16-Channel FET and 16-Channel Thermocouple FET Multiplexer Modules. This chapter contains the following sections:

∙ Commands for Scanning Switchbox Channels . . . . . . . . . . . Page 45 ∙ Using Scanning Trigger Sources . . . . . . . . . . . . . . . . . . . . . . Page 45 ∙ Using the Scan Complete Bit . . . . . . . . . . . . . . . . . . . . . . . . . Page 52

Commands for Scanning Switchbox Channels

Scanning multiplexer channels consists of closing a set of channels, one at a time. The multiplexer has single, multiple, or continuous scanning modes. See Figure 4-1 for the different commands used in scanning.

Using Scanning Trigger Sources

Scanning with External Instruments

The TRIGger:SOURce command specifies the source to advance the channel list. Figure 4-2 shows the different trigger sources. TRIG:SOUR DBUS uses the digital bus handshake lines. You can use the TRIG[:IMM] command to immediately advance the channel list while in the TRIG:SOUR BUS or TRIG:SOUR HOLD mode. (Note that TRIG:SOUR IMM is not the same as TRIG[:IMM].) To enable the HP E1300/E1301 Mainframe "Trig Out" port, use the OUTP ON command. The "Event In" mainframe trigger source is reserved with the TRIG:SOUR EXT command. "Trig Out" and "Event In" are mainframe resources, and can only be allocated to one instrument at a time.

The examples in this chapter show different ways to scan channels of a switchbox in an HP E1300/E1301 Mainframe. The operation is similar to other HP VXIbus mainframes with HP command modules that have "Trig Out" and "Event In" ports. The computer used in the examples is an HP Series 200/300 used with HP BASIC as the program language. The computer interfaces with the mainframe over HP-IB. Assumed is an:

∙HP-IB select code of 7

∙HP-IB primary address of 09 for the HP E1300/E1301 Mainframe

∙HP-IB primary address of 22 for the HP 3457A Multimeter

∙HP-IB secondary address of 14 for the multiplexer module

Chapter 4 Understanding the HP E1351A/53A FET Multiplexer Modules 45