5790B
Operators Manual
5-4
• Interface messages defined by IEEE standards have their own control lines,
and others are sent over the data lines by first asserting the control line ATN
(Attention). An important thing to note about interface messages is that unlike
device-dependent and common commands, interface messages are not sent
literally (in a direct way). For example, when a device-dependent query is
sent to the Product, the controller automatically sends the interface message
MTA (My Talk Address).
RS-232 Serial Interface
Use this section to control the Product from a terminal or computer with a serial
interface. This section describes how to set up the RS-232 interface for remote
control with protocol similar to IEEE-488. This section provides all details on data
transmission.
The RS-232 interface is designed in accordance with EIA (Electronic Industries
Association) standard RS-232.
RS-232 Interface Specifications
The RS-232 interface is configured as DTE (Data Terminal Equipment). You
must use a null-modem cable with two female 9-pin subminiature D connectors
to connect the Product to other DTE (Data Terminal Equipment) such as a typical
computer serial interface. The recommended shielded cable is a Fluke RS43.
Table 5-2 shows the choices available and the defaults for all programmable
interface parameters for the Product.
Table 5-2. RS-232 Interface Parameter Choices
Parameter Function Choices Default Setting
Data Bits Set number of data bits 7 or 8 8
Stop Bits Set number of stop bits 1 or 2 1
Flow Control/Stall
Ctrl S/Ctrl Q,
(XON/XOFF), RTS,
or none
Ctrl S/Ctrl Q
Parity Checking Select parity mode Odd, even, or none None
Baud Rate Set baud rate
9600, 19200,
38400, 57600, or
115200
9600
EOL (End of Line)
Set end of line
parameter
CR,LF, or CR LF CR LF
EOF (End of File)
Set end of line
character
Any two ASCII
characters
No characters