HP 3455A - Page 30

Section III
Model 345SA
Table
3-3.
Bus Massaeat.
Function* Message Description
Device
Communicsiion*
Data Transfers device-depettdent infor-
mation from one device to
orte or
more devices on the Bus.
Device
Control
Trigger
Cause*
a
group of selected devices
to
simultaneously imitate a set
of
device^ependent actions.
Clear
Causes an
instrument
to be set to
a
pre-defined state
la
certain
range, function,
etc.).
Remote
Permits selected devices to be set
to remote
operation, allowing
parameters and device cKaracteris-
tics to be
controlled
by Bus
Messages.
Local
Causes selected devices
to
return
to
local (front
panel)
operation.
Local
Lockout
Disables local (front panel) con-
trols of selected devices.
Clear
Lockout
and
Local
Returns
all devices
to
local (front
panel) control and simultaneously
clears the
Local
Lockout Message.
Interrupt
and
Rptriro
Require
Service
Indicates
a
device's need
for
inter-
action with the controller.
Status
Status
Byte
Presents status
information of
a
particular device; one bit indioetes
whether or not the device current-
ly
requires Service, the other
7
bits (optional) are used to
indi-
cate
the
type
of service required.
Status
Bit
A
single bit of device-dependent
status information
which may
be
logically combined
with
status bn
information from other devices
by the
controller.
Passing
Control
Pass
Control
Passes bus controller
responsibili-
ties
from the
current controller
to
a
device which can assume
the
Bus sutwrvisory
role,
Bail
Out
Abort
Unconditionally
terminates Bus
communications and returns con-
trol
to the system
controller.
data each
time a
measurement
sample is
made.
Section
of
FUNCTION.
RANGE.
TRIGGER, etc.
is ac-
complished
manually using
the front
panel
controls.
NOTE
When
the 34SSA is
connected
to a
system
with a
controller, the
TALK
ONLY
switch
must be
set to
the
off
position.
3-56.
Program Codas.
3-57.
All
front
panel
controls, except
the LINE
switch,
GUARD
switch,
and SAMPLE RATE switches, are
programmable
from the Bus. The program codes for
each control are listed in Table
3-4.
The program codes
can also be determined from the front panel markings.
For multi-control features such as FUNCTION,
RANGE, TRIGGER, and MATH the program code
consists of the combination of the underlined letter in
the control group heading
and the
position
number of
the particular control. See the following example:
CONTROL
GROUP CODE
(UNDERLINEOI
UfgCTION
—
tviAC
>wv bO
POSITtON
1
PROGRAM
FI
CODE
2 3 4
F2 F3
F4
«WII|
i
>0 Ttit
S
6
F5
F6
3-8