Rs-232 Modes Of Operation - Fluke 8845A Programmer's Manual

8845A/8846A
Programmers Manual

RS-232 Modes of Operation

RS-232 communication is slightly different between the 884X and Fluke 45 emulation
modes. Switching between these two commands sets is covered in the "Selecting the
Programming Language" section later in this manual. The following sections explain the
differences in communications protocol and how to set the Meter and computer
parameters for proper operation.
884X Mode
There are two modes of RS-232 operation when the Meter has the 884X command set
selected: TERMINAL and COMPUTER. The terminal mode is an interactive mode
where an operator inputs commands, with immediate returns for requested information
(queries) and interface messages. In terminal mode, characters sent to the Meter are
echoed on the host's display screen and a command prompt (for example 3>) is returned
after the CR/LF is entered by the terminal. If you send a character to the Meter over the
RS-232 interface, pressing the <DELETE> or <BACKSPACE> key deletes the previous
character. A backspace is echoed to the host terminal.
^C (CNTRL C) is the RS-232 equivalent of IEEE 488 DCI (device clear),
causing "1>" followed by a carriage return and line feed to be output.
The computer mode is used when the Meter is operated by computer program. In this
mode, requested information is returned by query, and interface messages are queued and
returned by command. Characters are not echoed on the host computer and command
prompts are suppressed. The <DELETE> or <BACKSPACE> keys are ignored.
Selecting Between Computer and Terminal Mode
Although you can select between Computer and Terminal mode at any time, the selection
is used only when the Meter's command mode is set to 884X.
To select computer or terminal mode from the front panel:
1. Press I and then PORT IF.
If the RS232 port is not already highlighted, press SELECT PORT and
then RS232.
2. Press either RS232, COMP/TERM ECHO and select either COMPUTER or
Fluke 45 Mode
In the Fluke 45 Command emulation mode, there are two modes of RS-232 operation:
ECHO or NO ECHO. In Echo mode, characters sent to the Meter are echoed on the
host's display screen. In No Echo mode, characters sent are not echoed.
To set the echo parameter, refer to the "Enabling and Disabling RS-232 Echo" section
earlier in this manual. If you send a character to the Meter over the RS-232 interface,
pressing the <DELETE> or <BACKSPACE> key deletes the previous character. A
backspace is echoed to the display screen if Echo On mode is set.
In either mode, when the host sends a command to the Meter over the RS-232 interface,
the Meter parses and executes the command, and returns a response if appropriate, and
sends one of three prompts:
8
TERMINAL.
Note
Note