HP 8340B Operating Instructions Manual page 90

LLO Local Lockout disables the instruments [LOCAL]-reset key; LLO is accomplished by
ASCir'DCI" (decimal 17).
MLA
MTA
PPC
PPU
SC
SCG
SDC
SPD
SPE
TA
TAD
TCT
UNL
My Listen Address (listen address of the controller).
My Talk Address (talk address of the controller).
Parallel Poll Configure (not used by the HP 8340B/41B).
Parallel Poll Unconfigure (not used by the HP 8340B/41B).
System controller.
Secondary command group (also abbreviated SEC).
Selected Device Clear, causes addressed instruments to clear to an instrument-defined state;
accomplished by ASCII "EOT" (decimal 4).
Serial Poll Disable, accomplished by ASCII "EM" (decimal 25).
Serial Poll Enable, accomplished by
responds with a byte of information,
function.
ASCII "CAN" (decimal 24). A serial polled instrument
with each bit corresponding to a specific instrument
Talker active state.
Talk Address of a specified device (see LAG for related information).
Take Control, transfers active controller responsibility to another instrument; accomplished
by ASCII "HT" (decimal 9).
Unlisten, clears bus of all listeners in preparation for assigning new listeners; accomplished
by ASCli"?" (decimal 63).
UNT Untalk, unaddresses the current talker so that no talker remains on the bus; accomplished by
ASCII (underscore, decimal 95).
These are the 12 bus messages (refer also to the HP-IB Command Statements that have the same
names as these messages):
DATA represents the actual transfer of numerical information between instruments. The pre¬
vious BASIC examples used OUTPUT and ENTER for data messages; the HP-IB bus
sequence for a typical OUTPUT statement is:
ATN MTA UNL LAG ATN (ASCII data) CR LF
The HP-IB sequence for a typical ENTER statement:
ATN UNL MLA TAG ATN (ASCII data) CR LF
TRIGGER causes the listening instruments to perform in instrument-defined function, such as
starting a sweep. A typical HP-IB sequence:
ATN UNL LAG GET (REN line must be True before executing GET)
CLEAR causes the listening instruments to establish an instrument-specific predefined state.
The HP-IB sequence:
ATN DCL (for ail bus instruments)
ATN UNL LAD SDC (for an addressed instrument)
HP 8340B/41B
Operating Information
3-87