Rs-232 Interface Configuration - HP 34401A User Manual

Chapter 4 Remote Interface Reference

RS-232 Interface Configuration

RS-232 Data Frame Format
A character frame consists of all the transmitted bits that make up a
single character. The frame is defined as the characters from the start bit
to the last stop bit, inclusively. Within the frame, you can select the
baud rate, number of data bits, and parity type. The multimeter uses
the following frame formats for seven and eight data bits.
Connection to a Computer or Terminal
To connect the multimeter to a computer or terminal, you must have
the proper interface cable. Most computers and terminals are
(Data Terminal Equipment) devices. Since the multimeter is also a
device, you must use a
DTE
called null-modem, modem-eliminator, or crossover cables.
The interface cable must also have the proper connector on each end
and the internal wiring must be correct. Connectors typically have
9 pins ( -9 connector) or 25 pins (
DB
or "female" pin configuration. A male connector has pins inside the
connector shell and a female connector has holes inside the connector shell.
If you cannot find the correct cable for your configuration, you may
have to use a wiring adapter. If you are using a
sure the adapter is a "straight-through" type. Typical adapters include
gender changers, null-modem adapters, and
Refer to the cable and adapter diagrams on the following page to
connect the multimeter to most computers or terminals. If your
configuration is different than those described, order the HP 34399A
Adapter Kit. This kit contains adapters for connection to other
computers, terminals, and modems. Instructions and pin diagrams are
included with the adapter kit.
-to- interface cable. These cables are also
DTE
-25 connector) with a "male"
DB
DTE
-9 to
DB
DTE
DTE
-to- cable, make
DTE
-25 adapters.
DB
149
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