Agilent Technologies 34901A User Manual page 54

Chapter 3 System Overview
Data Acquisition System Overview
The system configuration shown on the previous page offers the
following advantages:
• You can use the 34970A to perform data storage, data reduction,
mathematical calculations, and conversion to engineering units.
You can use the PC to provide easy configuration and data presentation.
• You can remove the analog signals and measurement sensors from
the noisy PC environment and electrically isolate them from both the
PC and earth ground.
• You can use a single PC to monitor multiple instruments and
measurement points while performing other PC -based tasks.
The Computer and Interface Cable
Since computers and operating systems are the subject of many books
and periodicals, they are not discussed in this chapter. In addition to the
computer and operating system, you will need a serial port ( RS -232) or
GPIB port ( IEEE -488) and an interface cable.
Serial (RS-232)
Advantages
Often built into the computer;
no additional hardware is
required.
Drivers usually included in
the operating system.
Cables readily available
and inexpensive.
The 34970A is
shipped with a serial cable
(if internal DMM is ordered).
* You can overcome these cable length limitations using special communications hardware.
For example, you can use the Agilent E5810A LAN-to-GPIB Gateway interface or a serial modem.
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Disadvantages
Cable length is limited Speed; faster data and
to 45 ft (15 m). * command transfers.
Only one instrument or Additional system flexibility,
device can be connected multiple instruments can
per serial port. be connected to the
same GPIB port.
Cabling is susceptible to Direct Memory Transfers
noise, causing slow or are possible.
lost communications.
Varying connector pinouts
and styles.
Data transfers up to Data transfers up to
85,000 characters/sec. 750,000 characters/sec.
GPIB (IEEE-488)
Advantages Disadvantages
Cable length is limited
to 60 ft (20 m). *
Requires an expansion
slot plug-in card in PC
and associated drivers.
Requires special cable.
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