Fluke 8842a instruction manual TALK-ONLY Mode, Addressed Commands

8842A

Instruction Manual

IFC	Interface Clear -- A uniline message which clears only the interface (not the
	8842A) by placing it in a known quiescent state.
REN	Remote Enable -- A uniline message which, when received with MLA, switches
	the 8842A to remote. When REN is set false, the 8842A switches to local and
	removes local lockout.
DCL	Device Clear -- A multiline message which is loaded into the input buffer as a
	special device-clear command. DCL performs the same operation as the device-
	dependent command *, except that it is read before any other characters that are
	already present in the input buffer, and clears the entire input buffer. Processing
	then continues normally. The action of DCL is not immediate; if the 8842A is
	taking a reading when DCL is received, the DCL command is executed after the
	measurement is finished.
LLO	Local Lockout -- A multiline message which disables the front panel LOCAL
	button. The result is that the local mode is not accessible by front panel control.
SPD	Serial Poll Disable -- A multiline message which removes the serial poll enable
	state.
SPE	Serial Poll Enable -- A multiline message which causes the serial poll data (rather
	than output buffer data) to be transferred on the bus once ATN becomes false.

3-55. Addressed Commands

Addressed commands are multiline messages which are accepted and interpreted by only those devices currently addressed to listen. The 8842A responds to the following addressed commands:

GET	Group Execute Trigger -- (Not to be confused with the device-dependent Get
	commands.) GET loads a trigger command into the input buffer and also
	terminates the string at that point. Only a single character is loaded into the input
	buffer. The trigger command is executed in its proper turn in the input string,
	rather than immediately. When executed, GET initiates a measurement.
GTL	Go To Local -- Causes the 8842A to switch to local. This command does not
	enter the input buffer. If the display has been blanked (with a D1 command),
	issue a D0 command before sending GTL.
SDC	Selected Device Clear -- Identical to the universal command DCL, but is
	accepted and interpreted by current listeners only. Therefore, it clears the 8842A
	only if it is addressed to listen.

3-56. TALK-ONLY MODE

The talk-only mode lets you take advantage of the remote capability of the 8842A without having to use an instrument controller. To put the 8842A in the talk-only mode:

1.Turn the 8842A POWER switch OFF.

2.Set the rear panel TALK ONLY bit switch to 1 (the up position).

3.Connect the 8842A via the IEEE-488 bus to your printer, data logger, or other device.

4.Configure the other device as a listener only.

5.Turn the 8842A POWER switch ON.

3-30