Signametrics Corporation SMU2060, Руководство оператора

Страница: 58 / 182

and negative widths of the pulse, as well as the number of pulses to be generated. Use
DMMSetDCVSource to set the pulse amplitude. The latter can be set to a level of -10V to +10V. The
inactive (or negative) portion is always at 0V while the active (positive width) is set to the specified level.
The widths can be set between 25µs and 3s. The widths values are set in base units (i.e. 0.05 for 50ms).
To stop the generator, issue
DMMDisableTrimDAC command. The pulse generator function requires
Driver version 1.60 and Microcode version 1.29 or higher.
Figure 4-21. Generating pulses is straight forward. It can be used for various test applications.
While the DMM is in this mode, it is possible to make DC voltage measurements. Using
DMMRead will
measure the average DC at the generator output. DMMReadHiSense , DMMReadLoSense and
DMMReadHiLoSense will measure the lower two terminals.
4.17 Interfacing to an external device
The SMU2060 series of Digital Multimeters are designed to interface to various external devices, be it
Multiplexers or component Handlers. A complete handshake can be established with either devices
triggering the other, with a response scheme. The following section describes both, the hardware interface
and the software functions required to implement a synchronized operation.
The SMU2060 series can provide a complete handshake with external devices such as SMU4030 series
Relays Scanners/Multiplexers, a component Handlers or another SMU2060 series DMM. The interface
can be as simple as a single line. For instance, connecting the SMU4032
TrigOut line to the SMU2060
Trigger input. The SMU4032 is setup to provide a ready signal, indicating to the DMM it can take a
measurement. The interface can also be a two way handshake, where the a DMM Sync pulse steps the
Scanner to the next point in it’s Scan List, and the SMU4032 generates a ready signal after the relays are
stable, indicating to the DMM to make a measurement etc.. The SMU2060 series can accept a trigger
input from many sources, and send out s Sync pulse of variable width. The trigger input can be setup as
positive or negetive edge or level. Due to the limited current the Sync output can provide, it may be
necessary to boost it with a single NPN or PNP transistor (see Figure 22).
Signametrics
58