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IEEE 488.2 GPIB, RS-232 OPTION FOR PULSERS
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Instruments with the -B suffix include a complete computer control interface. The
-B suffix allows instruments to be remotely controlled by a computer via the General-Purpose Interface
Bus (GPIB) or via a RS-232 serial port. The GPIB interface is IEEE 488.1 and IEEE 488.2 compliant.
The instrument command set is based on the easy-to-understand industry-standard "Standard Commands
for Programmable Instruments (SCPI)". Examples of typical commands are:
- frequency 1.2 kHz
- frequency 2.9e+4
- pulse:width 200ns
- pulse:delay?
As shown, numeric values can be specified with units, or in scientific notation. The last example is
a query command, which returns the current delay setting to the computer.
Instruments with the -B suffix normally share a common physical appearance and size (see the photos
below). These instruments feature a keypad and a back-lit liquid crystal display on the front panel. All
pulse parameters can be changed via the front panel or through the computer interface. The large display
normally shows all key parameters (such as frequency, pulse width, delay, amplitude, offset, trigger
mode, etc) simultaneously, for easy "at-a-glance" use. The front panel also has a "single pulse" button
for manually triggering a single pulse. The MAIN and SYNC output connectors are on the front panel,
and the EXT TRIG and GATE connectors are on the rear panel.
The interface contains memory to store up to four complete instrument setups. The
operator can use the front panel or the computer interface to store a complete "snapshot" of all key
instrument settings, and recall this setup at a later time. This simplifies the setup of frequently
performed experiments.
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Front panel of a typical -B suffix unit.
Rear panel of a typical -B suffix unit.
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The GPIBinterface is useful when a user wishes to control several instruments
from the computer. This approach requires a GPIB controller board in the user's computer.
(National Instruments is the recommended source of controller boards.) A two meter GPIB cable
is included with the -B instruments.
The RS-232 interface is a lower-cost approach to remote instrument control, since most computers
have at least one RS-232 serial port built-in. However, only one instrument can be attached to a
RS-232 port at a time. Avtech instruments with the -B suffix have a female 25-pin RS-232 connector
on the rear panel, and can be connected to a computer with a standard "straight-through" serial cable.
(This cable can be purchased at most computer stores. Several variations are available due to the
existence of several different types of RS-232 connectors on personal computers.)
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The resolution of the timing parameters varies, but is always better than 0.3% of the current setting.
(i.e. the setting can always be incremented or decremented by ± 0.3% or less), with two
exceptions. For the delay and pulse width at very low settings, resolution < 0.3% of (PW or delay
+20ns). For frequencies between 0.1 Hz and 1 Hz, the resolution is < 0.7%. The amplitude and
offset parameters typically have a resolution of 0.03% of the full-scale setting. Accuracy is typically
± 3%. Pulse width and delay RMS jitter for instruments with the -B suffix option is typically
± (35ps + 0.015% of PW or delay).
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any further enquiries. Monday through Friday, 9 am to 6 pm, Singapore Standard Time, call
(65)-4409746 or email us anytime at smart_sense@yahoo.com. We
response within 24 hours.
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