120

TRIGGER 70903

!Trigger the switchbox to advance

 

 

the channel list

130

NEXT I

!Increment count

140

END

 

Scanning Voltmeter When the multiplexer(s) is combined with a multimeter to form a single instrument, they become a virtual instrument, a scanning voltmeter. The multiplexer(s) and the multimeter have the same secondary address. The multimeter automatically configures the multiplexer, so the SCAN:MODE, SCAN:PORT and TRIG:SOUR commands are not required. Channel advance is from the digital bus handshake lines, so the count loop is not required. The ARM:COUN command does not apply to downloaded scan lists, so you cannot specify the number of cycles through the scan list. You can, however, specify INIT:CONT ON for continuous scanning through the scan list.

10

DIM Rdgs(1:16)

!Dimension an array for 16

 

 

readings

20

OUTPUT 70903;"*RST"

!Reset instrument

30OUTPUT 70903;"MEAS:VOLT:DC? (@100:115)"

!Configure instrument

40

ENTER 70903;Rdgs(*)

!Enter readings into array

50

PRINT Rdgs(*)

!Print results

60

END

 

Digital Bus and Triggering

The HP E1351A/E1353A can be triggered for channel advance from the VXIbus backplane or through the digital bus handshake cable on the front of the component assembly. Backplane triggering can come from HP-IB computer commands over the HP-IB Bus or from the HP E1300/1301 Mainframe "Event In" port. Digital bus triggering uses two handshake lines; channel advance and channel closed. Channel advance (input to multiplexer) triggers an advance, and channel closed (output from multiplexer) signifies advance completed.

The HP E1326B Multimeter has a digital bus port on the face plate, and connects to the multiplexer with the digital bus cable (see Figures 2-10 and 2-11). To connect other multimeters for digital bus triggering, you must prepare a custom cable. Use a connector like the one on the digital bus cable (HP part number E1300-61611). Connect the measurement complete port from the multimeter to the channel advance pin, and the external trigger to the channel closed pin. Connect the grounds for both signals to the digital bus ground (second pin from right). You can use this cable to connect an external multimeter to a switchbox, and then use TRlG:SOUR DBUS (digital bus triggering). You can also order a custom cable with BNC to digital bus connectors, HP part number E1411-80001. See Figure 2-11 for more information on multiplexer-to-multiplexer and multiplexer-to-multimeter connections.

Chapter 1

Getting Started with the HP E1351A/53A 15