Table of Contents
Advertisement
General Bus Commands
B.3
IFC (Interface Clear)
The IFC command is sent by the controller to place the Mod-
el 6512 in the local, talker, and listener idle states. The unit
will respond to the IFC command by cancelling front panel
TALK or LISTEN lights, if the instrument was previously
placed in one of those modes.
B.4
LLO (Local Lockout)
The LLO command is used to remove the instrument from
the local operating mode. After the unit receives LLO, all its
front panel controls except POWER will be inoperative.
REN must be true for the instrument to respond to LLO.
REN must be set false to cancel LLO.
B.5
GTL (Go To Local)
The GTL command is used to take the instrument out of the
remote mode. With some instruments, GTL may also cancel
LLO. With the Model 6512, however, REN must first be
placed false before LLO will be cancelled.
B.6
DCL (Device CIear)
The DCL command may be used to clear the Model 6512
and return the unit to its power-up default conditions. Note
that the DCL command is not an addressed command, so all
instruments equipped to implement DCL will do so simulta-
neously. When the Model 6512 receives a DCL command, it
will return to the default conditions listed in Table B-2.
B.7
SDC (Selective Device Clear)
The SDC command is an addressed command that performs
essentially the same function as the DCL command. Howev-
er, since each device must be individually addressed, the
SDC command provides a method to clear only a single, se-
lected instrument instead of clearing all instruments simulta-
B-2
neously, as is the case with DCL. When the Model 6512
receives the SDC command, it will return to the power-up
default conditions listed in Table B-2.
Table B-2
Default conditions
Mode
Function
Range
Zero Check
Zero Correct
Suppression
Trigger
Data Format
Data Store
SRQ Mode
EOI and Bus Hold-off
Terminator
* Indicates corresponding device-dependent command and option; see Section 3.
** Instrument status on power-up, or after receiving DCL or SDC.
B.8
GET (Group Execute Trigger)
GET may be used to trigger the Model 6512 to take readings if
the instrument is placed in one of the two GET trigger modes.
More information on trigger modes may be found in Section 3.
B.9
Serial polling (SPE, SPD)
The serial polling sequence is used to obtain the Model 6512
status byte. The status byte contains important information
about internal functions, as described in Section 3. General-
ly, the serial polling sequence is used by the controller to de-
termine which of several instruments has requested service
with the SRQ line. However, the serial polling sequence may
be performed at any time to obtain the status byte from the
Model 6512.
Default
value*
Status**
F0
Volts
R0
Auto-range
C1
Enabled
Z0
Disabled
N0
Disabled
T6
Continuous, External
G0
Prefix, no suffix
Q7
Disabled
M00
Disabled
K0
Both disabled
Y=:
<CR> <LF>
Advertisement
Table of Contents
