Rs-232 Interface Configuration - HP 34970A User Manual

Chapter 5 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 bits 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 instrument uses the following
frame formats for seven and eight data bits.
Start
Parity:
Bit
EVEN, ODD
Parity: Start
Bit
NONE
Connection to a Computer or Terminal
To connect the instrument to a computer or terminal, you must have
the proper interface cable. Most computers and terminals are DTE
(Data Terminal Equipment) devices. Since the instrument is also a DTE
device, you must use a DTE -to- DTE interface cable. These cables are
also 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 ( DB -9 connector) or 25 pins ( DB -25 connector) with a "male"
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 DTE -to- DTE cable, make sure
the adapter is a "straight-through" type. Typical adapters include
gender changers, null-modem adapters, and DB -9 to DB -25 adapters.
272
Parity
7 Data Bits
Bit
8 Data Bits
Stop
Bit
Stop
Bit