BNC 845-M Operating and maintenance manual
1
Model 845-M
Programmer’s
Manual
Version
1.1, June
2011
Berkeley Nucleonics Corporation
2955 Kerner Blvd, San Rafael CA 94901 USA- www.berkeleynucleonics.com
Chat online or email info@berkeleynucleonics.com- Toll Free: 800-234-7858, Fax: 415-453-9955
2
Model 845-M Programmer’s
Manual
V1.1 2011
Contents
1.
Introduction
.......................................................................................................................................................
3
2.
Programming
the
Model 845-M…….
...................................................................................................................
4
L
AN...........................................................................................................................................................4
Ethernet Interface
Connection
and
Setup
..............................................................................................4
Using Sockets LAN
.....................................................................................................................................6
Using
and
Configuring VXI-11
(VISA)
.......................................................................................................6
Using
Telnet
LAN
......................................................................................................................................
7
USB
(fully supportedfrom Firmware 0.4.0 upwards)............................................................................7
USB-TMC
Interface
Connection
and Setup
usingVISA.............................................................................
7
USB-TMC
Interface
Connection
and Setup
using BNC API
......................................................................8
GPIB
Interface
Connection
and
Setup
.....................................................................................................8
Using
SCPI
…………
.................................................................................................................................8
3.
IEEE-488
Interface
Commands
..........................................................................................................................
9
IEEE
Mandated
Commands
......................................................................................................................
9
4.
SCPI
Commands..................................................................................................................................................
12
Introduction
.............................................................................................................................................
12
SCPI
Command Types
...............................................................................................................................
13
SCPI
Command Syntax
.............................................................................................................................
13
Hierarchical Command
Structure.............................................................................................................
14
Status System
Programming ...................................................................................................................
15
SCPI
Command
Descripti
on.......................................................................................................................
19
:ABORt
Subsystem
.....................................................................................................................................
19
:DISPlay
Sub
s
ystem
....................................................................................................................................
20
:INITiate Subsystem
...................................................................................................................................
21
[SOURce]:FREQuency Subsystem
.............................................................................................................23
[SOURce]:PHASe
Subsystem
......................................................................................................................
25
[SOURce]:POWer Subsystem
.....................................................................................................................
26
[SOURce]:ROSCillator Subsystem
..............................................................................................................
28
[SOURce]:LISTSubsystem
...........................................................................................................................
29
[SOURce]:LFOutput Subsystem
................................................................................................................32
[SOURce]:SWEep Subsystem
.....................................................................................................................34
[SOURce]:AM Subsystem
(Amplitude Modulation) .................................................................................35
[SOURce]:FM Subsystem (Frequency
Modulation)
...................................................................................
37
[SOURce]:PM Subsystem (Phase
Modulation)..........................................................................................
39
[SOURce]:PULM
Subsystem
(Pulse
Modulation)
......................................................................................
4
0
:TRIGger
Subsystem
..................................................................................................................................
42
:STATus
Subsystem
....................................................................................................................................45
:SYSTem
Sub
s
ystem
...................................................................................................................................
47
[:SYSTem:COMMunicate] Subsystem
......................................................................................................48
UNIT
Subsystem
.........................................................................................................................................
51
Company
De
tails
....................................................................................................................................................
52
3
Model 845-M Programmer’s
Manual
V1.1 2011
1.
Introduction
This
manual
provides
information for remote operation of the
Model 845-M Signal Generator
using
commands
sentfrom an external
controller
via Ethernet. It
includes
the
fol
l
owing:
x A general
description
of the
LAN
and the
bus
data transfer and controlfunctions
x A general
description
of how to
establish connection
to the
Model 845-M
via
LAN, USB,
or
GPI
B
x A listingof the
IEEE-488
Interface
Fun
c
tion
Messages recognized
by the
signal
genera
to
r
with a
description
of its response
x A
complete
listing and
description
of all the Standard
Commands
for Programmable
Instruments
(SCPI) commands
that
can
be
used
to control
signal
generator operation
wit
h
examples
of
command
usage
4
Model 845-M Programmer’s
Manual
V1.1 2011
2.
Programming
the
Model 845-M
The
Model
845-M
can
be
accessed
though
LAN, USB,
or
GIPB
interface. All
interface
s
use standard
SCPI
command
set to
pass commands
to the device.
LAN
The
Model
845-M
signal
generator
can
be remotely programmed via a
10/100/1000Base-T LAN
interface and
LAN-connected computer using
one of
several LAN
interface
protocols.
The
LAN
allows
instruments
t
o
be
connected
together and
controlled
by a
LAN- based computer. LAN
and its
associated
interface operationsare
defined in the
IEEE
802.2 standard.
The
Model
845-M
supports the following
LAN
interface protocols:
1) Socket based LAN:
the application programming interface
(API)
provided with
the
instrument
supports
general programming
using
the
LAN
interface under Windows operating system.
2) VXI-11
3)
Telephone
Network
(TELNET): TELNET is used
for interactive, one
command
at a time
instrument control.
4) Internet
protocol
optionally supported
For LAN
operation, the
signal
generator mustbe
connected
to the
LAN,
and an
IP address
mustbe
assigned
to the
signal
generator either manually or by
using DHCP
client
service.
Your system
administrator
can
tell you which method to
use.
(Most current
LAN
networks
use
DHCP.)
DHCP
Configuration
If the
DHCP server uses dynamic DNS
to link the hostnamewith the
assigned IP address,
the hostname may be
used
in
place
of the
IP address.
Otherwise, the
hostname is
not usable.
Ethernet Interface Connection and Setup
The
Model
845-M
fully
supports
the
IEEE-802.3standard.
Most front panel
functions
(except
power
on/off)
can
be remotely
c
ontrolled via a network
s
erver
and an Ethernet
connection.
The
Model
845-M
software
supports
the
TCP/IP
network protocol.
Ethernet
uses
a
bus
or startopologie
s
where all of the interfacing
devices
are
connected
to a central
cable
called
the
bus,
or are
connected
to a hub. Ethernet
uses
the
CSMA/CD
access
method to handle
simultaneou
s
transmissions
over the
bus. CSMA/CD stands
for
Carrier Sense
Multiple Access/Collision Detection.
This standard
enables
network
devices
to detect
simultaneous
data
channel usage, called
a
collision
,
and
provides
for a
contention
protocol.
When a network
device detects
a
collision,
the
CSMA/CD standard dictates
that the data
will be retransmitted after waiting a random amount
of
time. If a
second collision is
detected, the data
is
again retransmitted after waiting twice
as
long. This
is
known
as
exponential
back
off.
The
TCP/IP
s
e
tup
require
s
the
following:
5
Model 845-M Programmer’s
Manual
V1.1 2011
•
IP Address:
Every computer/electronic device
in a
TCP/IP
network
require
s
an
IP address.
An IP
address has
four
number
s
(each
between 0 and
255) separated
by periods.
For
example: 192.168.1.50 is
a valid
IP
address.
•
SubnetMask:The subnet
mask distinguishes
the portion of the
IP address
that
is
the network ID from the
portion that
is
the station ID. The subnet
mask 255.255.0.0,
when applied to the
IP
address given above,
would identify the network ID
as 192.168
and the station ID
as 1.50.
All
stations
in
the
same local
area
network
s
hould
have the
same
network ID, but different station IDs.
•
Default Gateway: A
TCP/IP
network
can
have a gateway to
c
o
mmunicate
beyond the
LAN
identifi
ed
by the
network ID. A gateway
is
a
computer
or
electronic device
that
is connected
to two
different
networks and
can
move
TCP/IP
data from one network to the other. A
single LAN
that
is
not
connecte
d
to other
LANs requires
a
default gateway setting of 0.0.0.0. If you have a gateway,
then
the
default gateway would be setto the
appropriate value of your
gateway.
•
MAC
Address:
A MAC
address is
a unique 48-bit value that identifies a network interface
card
to
t
he
restof
the network.
Every
network
card has
a unique MAC
address
permanently stored into its memory.
Interface between the
signal
generator and other
devices
on the network
is
via a categoryfive (CAT-
5) interface
cable connected
to a network.
This cable uses
four twisted
pairs
of
copper
insulators terminated
into an
RJ45connector. CAT-5 cabling is capable
of supporting
frequencies
up to
100
MHz
and data transfer
speeds
up to
1 Gbps,
which
accommodates 1000Base-T, 100Base-T,
and 10Base-T networks.
The instrument
can
be remotely programmed
using
the
VXI-11protocol.
A
VISA
I/O library (like NI-
VISA™) is
used
on the
server side
to facilitate the
communications.
A
VISA
installation on
the
controller is
a
prerequisite
for remote controlover
LAN
interface.
VISA is
a
s
tandar
dized
software
interface library
providing input and output
functions
to
communicate
with
instruments. For
more information about
VISA
refer to the
VISA
library
supplier’s
documentation.
The
SCPI
command
set listedin the
Model
845-M
programmer’s
manual
applies
to LAN programming
as
well.
Only the
IP address
or the
device
name
is
required for link setup.The
IP address/device
name
is
part
of the
"visa resource
string"
used
by the
programs
for identification and controlof the instrument. The
visa
resource
string
has
the form:
TCPIP::ipa
ddr::inst0::INSTR
ipaddr
has
to be
replaced
by the
IP address
or the
computer
name of the instrument.
6
Model 845-M Programmer’s
Manual
V1.1 2011
For instance,
if the instrument
has
the
IP address 192.168.1.50,
TCPIP::192.168.1.50::inst0::INSTR
is
the
valid
resource
name.
Specification
of inst0 in the
resource
name
is
optional. In this example, also
TCPIP::192.168.1.50::INSTR
is
therefore a valid
resource
name.
TCPIP designates
the network protocol
used
and
INSTR indicates
that the
VXI-11protocol is used.
If
several
instruments
are
c
onnecte
d
to the network,
each
instrument
has
its own
IP address
and
associated resource
name. The
controller
identifies these
instruments
by
means
of the
resource
name.
Using
Sockets
LAN
Sockets LAN is
a method
used
to
communicate
with the
signal
generator over the
LAN
interface using the
Transmission Control
Protocol/Internet
Protocol (TCP/IP).
A
socket is
a fundamental technology
used
for
computer
networking and allows
applications
to
communicate using standard
mechanisms built into network
hardware and operating
systems.
The method
accesses
a port on the signal generator from which
bidirectional
communication
with a network computer
can
be
e
s
tablished.
Sockets LAN can
be
described as
an internet
address
that
combines
Internet
Protocol (IP)
with a device port number and
represents
a
single connection
between two
pieces
of software. The
socket can
be
accessed using code libraries packaged
with the
computer
operating
system.
Two
common versions
of
socket libraries
are the
Berkeley
Soc
ke
t
s
Library
for UNIX
systems
and
Winsock
for Microsoft
operating systems.
Your
signal
generator
implements
a
socket Applications Programming
Interface
(API)
that is compatiblewith
Berkeley socket
for UNIX
systems,
and
Winsock
for Microsoft
systems.
The signal generator
is also
compatible
with other
standard sockets APIs.
The
signal
generator
can
be controlled
using
predefined
SCPI functions once
the
socket
c
onnection
is established
in your program. Socket
connection is
available on port 18.
Using and Configuring
VXI-11
(VISA)
The
signal
generator
supports
the
LAN
interface protocol
described
in the VXI-
11
standard.
VXI-
11
is
an instrument controlprotocol
based
on Open Network Computing/Remote
Procedure Call
(ONC/
R
P
C
)
interfaces
running over
T
C
P/IP.
A range of
standard
software
such as NI-VISA
or Agilent IO Config
is
available to setup
the
computer/signal
generator interface for the VXI-
11
protocol. Please
refer to the
applicable
software
user
manual and
documentationfor information on running the program and
configuring
the VXI-11 interface. The program
is used
to
configure
the
LAN
client.
Once
the
computer is
configuredfor a LAN client, you
can use
the VXI-
11
protocol
and the
VISA
library to
send SCPI commands
to the signal generator over the
LAN
interface.
7
Model 845-M Programmer’s
Manual
V1.1 2011
VISA is
an IO library
used
to develop IO
applicatio
n
s
and instrument
drivers
that
comply
with industry
standards.
It
is recommended
that the
VISA
library be
used
for programming the
signal
generator. The
NI-VISA
and Agilent
VISA libraries
are
similar
implementations of
VISA
and have the
same
commands, syntax,and
functions.
Using Telnet LAN
Telnet
provides
a
means
of
communicating
with the
signal
generator over the
LAN.
TheTelnet client, run on
a
LAN connected
computer,will create a login
session
on the
signal
generator. A connection,
established
between
computer
and
signal
generator, generatesa
user
interface
display screen
with
“>”
prompts
on the
command
line.
Using
the Telnet
protocol
to
send commands
to the
signal
generator
is similar
to
communicating
with
the
signal
generator over
LAN.
You
establish
a
connection
with the
signal
generator and then
send
or
receive
information
using
predefined
commands. Communication is interactive:
one
command
at a time. The telnet
service is
available on port 18.
Once
a telnet
session
to the
device is established,
the
echo can
be enabled by
typing
SYST:COMM:SOCK:ECHO
ON
Following this
command
a prompt “>>”
should become
visible.
USB
(fully supported from Firmware 0.4.0
upwards)
The
Model
845-M
supports the following
USB
interface
pro
t
o
c
ols:
1) USBTMC class device
via VISA
2)
USBTMC:
the applicationprogramming interface
(API)
provided with the instrument
supports
general programming
using
the
USB
interface under Windows operating system.
USB-TMC
Interface Connection and Setup using VISA
USBTMC stands
for
USB Test
& Measurement
Class. USBTMC is
a
protocol
built on top of
USB
that
allows
GPIB-
like communication
with
USB devices. From
the
user's
point of view, the
USB
device
behave
s
just like a
GPIB
device. For
example, you
can use VISA
Write to
send
the *IDN? query and use
VISA Read
to get the
response.
The
USBTMC
protocol
supports service
request,
triggers
and other
GPIB
specific
operations.
USBTMC upgrades
the
physical
layer from
GPIB
to
USB
while maintaining software compatibility
with
existing
software,
such as
instrument
drivers
and any
application
that
uses VISA. This is also
what
the
VXI-11protocol
provides
for TCP/IP.
8
Model 845-M Programmer’s
Manual
V1.1 2011
NI-VISA
3.0 or later allows you to
communicate as
a
controller
to
Model
845-M
. NI-VISA is
configured to detect
USBTMC compliant instruments such as
the
Model
845-M
.
To
use such
a
device,
plug it in and Windows
should
detect the new hardware and
launch
the New Hardware Wizard.
Instruct
the
wiza
rd
to
search
for the driver,
which in this
case is NI-VISA.
If
NI-VISA is
properly
installed,
the
device
will be
installed as
a
USB Test
&
Measurement
Class Device.
Open Measurement & Automation Explorer (MAX). The new
device
will appear in
MAX under
Device
and
Interfaces
»
USB Devices.
You
can
then
use
this
resource
name
as
you would
use
any
GPIB
resource.
USB-TMC
Interface Connection and Setup using BNC API
BNC API
programming interface
supports
dire
c
t
communication
to
Model
845-M
using
BNC’s proprietary
DLL
driver
libraries.
Thelibrary allows setupa
communication channel
though
USB, LAN
, or
GPIB
from any
programming environment.
Please
cont
a
c
t
Berkeley Nucleonics
for more detailed documentation, programming
samples,
and
updates
on
th
e
DLL
library.
GPIB
Interface Connection and Setup
This
documentation
is
available in an updated
version
of this
programmer’s
manual.
Using
SCPI
for Mode1 845-M
The
Standard Commands
for
Programmable
Instrumentation
(SCPI) provides
a uniform and consistent
language to controlprogrammabletest and
measurement devices
in instrumentation
systems.
The
SCPI
Standard
is
built on the foundation of
IEEE-488.2, Standard Codes
and
Formats.
It requires
conformance
to
IEEE-488.2,
but
is
pure software
standard.
SCPI
syntax
is ASCII
text, and therefore can be attached to any
computertest language,
such as BASIC, C,
or
C++.
It
can also
be
used
with Test
Application
Environmen
t
s
such
as
LabWindows/CVI, LabVIEW™,
or Matlab®.
SCPI is
hardware
independent.
SCPI strings can
be sent over any
instrument interface. It works equally well over USB- TMC,
GPIB, RS-232, VXIbus
or
LAN
networks.
Please see
the
chapter
4 for detailed
description
of supported
SCPI
commands.
9
Model 845-M Programmer’s
Manual
V1.1 2011
3.
IEEE-488
Interface Commands
IEEE
Mandated Commands
Therequired
common commands
are
IEEE-488.2
mandated
commands
that are defined in
the
IEEE-
488.2standard
and mustbe implemented by all
SCPI
compatible
instruments.
The
s
e
commands
are
identified by the
asterisk
(*) at the beginning of the
command
keyword. These
commands
are
used
to controlinstrument
status registers, status
reporting, synchronization, and other
common
functions.
Commands declared
mandatory by
IEEE
488.2.
*CLS Clear Status
Command
*ESE
StandardEvent
Status Enable
Command
*ESE?
StandardEvent
Status Enable
Query
*ESR?Standard
Event
Status Register
Query
*IDN? Identification Query
*OPCOperation CompleteCommand
*OPC?
Operation CompleteQuery
*RST Reset
C
ommand
*SRE Service Request Enable
Command
*SRE? Service Request Enable
Query
*STB? Read Status
ByteQuery
*TST? Self-Test
Query
*WAI Wait-to-Continue
C
ommand
*CLS
The
Clear Status (CLS) command clears
the
status
byte by emptying the error queue and clearing all the
event
registers including
the Data
Questionable
Event
Register,
the
Standard
Event
Status Register,
the StandardOperation
Status Register
and any other
registers
that are
summarized
in the
status
byte.
*ESE <da
ta>
The
Standard
Event
Status Enable (ESE)
command sets
the StandardEvent
Status
Enable
Register.
Thevariable <data>
represents
the
sum
of the bitsthat will be enabled.
Range
0–255
Remarks
Thesetting enabled by this
command is
not affected by
signal
generator presetor
*RST.
However,
cycling
the
signal
generator power will resetthis
register
to zero.
*ESE?
The
Standard
Event
Status Enable (ESE)
query returnsthe value of the
Standard
EventStatus
Enable
Register.
*ESR
?
The
Standard
Event
Status Register (ESR)
query
returns
the value of the
Standard
EventStatus
Register.
NOTE: Reading
the
Standard
Event
Status Register clears
it
10
Model 845-M Programmer’s
Manual
V1.1 2011
Remarks
The
Register is
not affected by
signal
generator presetor
*RST.
However,
cycling
the
signal
generator power will resetthis
register
to zero.
*IDN?
The Identification (IDN) query outputs an identifying string.The
response
will show
th
e
following information:
<company
name>, <model number>,
<serial
number>,
<firmware
revision>
*OPC
The Operation Complete
(OPC) command sets
bit 0 in the
Standard
Event
Status Register
when
all
pending operationshave finished.
The Operation Complete
command causes
the
device
to setthe operation
complete
bit (bit 0) in the
Standard
Event
Sta
tu
s
Register
when all pending operation
s
have been finished.
*OPC?
The Operation Complete
(OPC)
query returnsthe
ASCII character
1
in the
Standard Event
Status
Register
when all pending
operations
have finished.
This
query
stops
any new
commands
from being
processed
until the
current processing
is complete.
This command blocks
the
communication
until all
operations
are
complete
(i.e.
the
timeout setting
should
be longer than the
longest
s
w
eep).
*OPT?
The
options (OPT)
query returnsa
comma-separated
list of all of the instrument
option
s
currently
installedon the
signal
generator.
*PSC
ON|OFF|1|0
The Power-On
Status Clear (PSC)command controls
the automatic power- on
clearing
of
the
Service
Request Enable Register,
the
Standard
Event
Status Enable Register,
and
device-
specific
event enable
registers.
ON
(1) This choice enable
s
the power- on
clearing
of the listed registers.
OFF
(0
)
This
choice
disables
the
cleari
ng
of
the
listed
registers
and
they
re
t
ain
their
stat
us
when
a power- on
condition
occurs.
*PSC
?
The
Power-On
Status
Clea
r
(PSC
) query
returns
the
flag
setting
as
enabled by
the
*PSC
command.
*RCL
<reg>
The
Recall (RCL)command recalls
the state from the
specified
memory
regi
s
ter
<reg>.
*RST
aff
ected
The
Reset (RST) command resets
most
signal
generator
function
s
to factory- defined conditions.
Remarks Each command shows
the
[*
RST]
default value if the setting
is
affected.
*SAV <reg>
The
Save (SAV) command saves signal
generator
settings
to the
specified
memory
regi
s
ter
<reg>.
Remarks
The
save
function
does
not
save
all
signal
generator
settings.
Referto the
User’s
Guide
for more information on the
save
fu
n
c
tion.
*SRE
<dat
a>
11
Model 845-M Programmer’s
Manual
V1.1 2011
The
Service Request Enable (SRE) command sets
the value of the
Service Request
Enable
Register.
The
variable <data>
is
the
decimal sum
of the bits that will be enabled. Bit 6 (value 64)
is
ignored and
cannotbe set by this command.
Range
0–255
The setting enabled by this
command is
not affected by
signal
generator preset or
*RST.
However,
cycling
the
signal
generator power will resetit to zero.
*SRE
?
The
Service Request Enable (SRE)
query returnsthe value of the
Service Request
Enable
Register.
Range
0–63& 128-191
*STB
?
The
Read Status
Byte
(STB)
query returnsthe value of the
status
byte
including
the master
summary status (MSS)
bit.
Range
0–255
*TRG
The Trigger
(TRG)command triggers
the
device
if
LAN is
the
selected
trigger
source,
otherwise,
*TRG
is
ignored.
*TST?
The
Self-Test (TST)
query initiates the internal self-test and returnsone of the following results:
0
This shows
that all
tests
passed.
1
This shows
that one or more
tests
f
ailed.
*WAI
The Wait- to-
Continue
(WAI)
command causes
the
signal
generator to wait until all pending
commands
are
completed,
before
executing
any other commands.
12
Model 845-M Programmer’s
Manual
V1.1 2011
4.
SCPI
Commands
This chapter provides
an introduction to
SCPI
programming that
includes descriptions
of
the
command
types,
hierarchical command structure,
data
parameters,
and notational conventions. Information on
status system
and trigger
system
programming
is also
provided.
Introduction
Standard Commands
for
Programmable Instruments
(SCPI) is
the new instrument command language for
controlling
instruments
that
goes
beyond
IEEE
488.2to
address
a wide variety
of
instrument
functions
in a
standard
manner.
SCPI
promotes consistency,
from the
remo
te
programming standpoint, between
instruments
of the
same class
and between instruments
with
the
same
functional capability.
For
a
given
measurement
function
such as
frequencyor voltage,
SCPI
definesthe
specific command
setthat
is
available for that function.
Thus,
two
oscilloscopes
made by different
manufacturers could
be
used
to
make
frequency
measurements in the
same
way. It
is also possible
for a
SCPI
counterto make a
frequency
measurement
using the
same commands as
an
oscilloscope. SCPI commands
are
easy
to learn,
self-explanatory and
account
for both
novice
and expert
programmer’s usage. Once
familiar with the
organization and
structure
of
SCPI,considerable efficiency gains can
be
achieved
during control
program development, independent of the
control
program language selected.
A key to
consistent
programming
is
the
reduction
of multiple ways to control
similar
instrument
functions.
The
philosophy
of
SCPI is
for the
same
instrument
functions
to be controlledby
the
same SCPI
commands.
To
simplify
learning,
SCPI uses
industry-standard
name
s
and terms
that
are
manufacturer
and
customer
supported.
The advantage of
SCPI
for the
ATE system
programmer
is reducing
the time learning how
to
program new
SCPI
instruments
after programming their first
SCPI
instrument.
Programmer
s
who
use
programming
language
s
such as BASIC, C, FORTRAN,
etc.,to send instrument
commands
to
instruments
will benefit from
SCPI.
Also, programmers
who
implement instrument
device drivers
for
ATE
program
generators
and/or
s
o
ftware
instrument front
panels
will benefit by
SCPI’s
advantages.
SCPI
definesinstrument
commands,
parameters, data, and
status.
It
is
not an
application
package,
programming language or software
int
ended
for instrumentfront panel
control.
SCPI is designed
to be layered on top of the hardware-independent portion of
IEEE
488.2.
13
Model 845-M Programmer’s
Manual
V1.1 2011
SCPI
Command Types
SCPIcommands,
which are
also
referred to
as SCPI
instructions,
are
messages
to the instrument to
perform
specific tasks.
The
Model
845-M
c
ommand
setincludes:
x
“Common” commands (IEE488.2
mandated commands)
x
SCPI
required commands
x
SCPI
optional
commands
(per
SCPI
1999.0)
x
SCPI
compliant
commands
that are unique to the
Model
845-M
.
Not all of the commands
supported
by the instrument are taken from the
SCPI standard;
however, their syntax
follows
SCPI
rules.
SCPI
Command Syntax
Typical SCPI commands consist
of one or more keywords,
parameters,
and punctuation. SCPI
command
keywords
can
be a mixture of upper and lower
case characters. Except
for common
commands, each
keyword
has
a long and a shortform. In this manual, the long form is
presented
with the shortform in upper
case
and the remainder in lower case. Unrecognized
versions
of long
form or shortform
commands,
or improper syntax,will generate an error.
Structure
of a
Command
Line
A
command
line may
consist
of one or
several commands.
It
is
terminated by an
EOI
to
gether
with
the lastdata
byte.
Several commands
in a
command
line must be
separated
by a
semicolon
";". If the
next
command
belongs
to a different
command system,
the
semicolon is
followed by a
colon.
A
colon
":" at the
beginning of a
command marks
the root node of the
command
tree.
If the
successive commands
belong to the
same system,
having one or
several levels
in common, the
command
line
can
be abbreviated. Tothis end, the
second
c
ommand
after the semicolon
starts
with the
level that
lies
below the
common levels.
The
colon
following the
semicolon
must be omitted in this
case.
Responses
to Queries
A query
is
defined for
each
setting
command unlessexplicitly specified
otherwise. It
is
f
ormed by
adding a
question
mark to the
associated
setting
command. According
to
SCPI,
the responses to
queries
are partly
subject
to
stricter rules
than in
standard
IEEE
488.2.
14
Model 845-M Programmer’s
Manual
V1.1 2011
Parameters
Most
commands
require a parameter to be
specified.
The
parameters
mustbe
separated
from
the
header by a "white
space". Permissible parameters
are
numerical values,
Boolean
parameters,
text,
character strings
and
block
data. Thetype of parameter required for
th
e
respective command
and
the
permissible
range of
values
are
specified
in the command description.
Numerical values Numerical values can
be entered in any form, i.e. with
sign, decimal
point and
exponent.
Values exceeding
the
resolution
of the instrument are rounded up or down. The
mantissa
may
comprise
up to
255 characters,
the
values
mustbe in the value range
–9.9E37
to
9.9E37.
The exponent
is
introducedby an
"E"
or "e". Entry of the exponent alone
is
not
allowed.
UnitsIn the
case
of
physical
quantities,the unit
can
be entered.
Permissible
unit
prefixes
are G (giga),
MA (mega), MHZ are
also permissible),
K (kilo), M (milli), U
(micro)
and N (nano). If
the
unit
is missing,
the
basic
unit
is
used.
Boolean Parameters Boolean parameters represent
two
states.
The ON state
(logically
true) is
represented
by ON or a
numerical
value unequal to 0. The
OFF
state
(logically
false)is
represented
by
OFF
or the
numerical
value 0. ON or
OFF is
returned by a query.
HierarchicalCommand Structure
All
SCPIcommands,
exceptthe
common commands,
are organized in a
hierarchical
structure
similar
to the inverted tree file
structure used
in most
computers.
The
SCPI
standard
refers
to
this
structure
as
“the
Command Tree.”
The
command
keywords that
correspond
to the major instrument
c
ontrol
functions
are locatedat the top of the
command
tree. The command keywords for the
Model
845-M
SCPIcommand
setare shown
below.
:ABORt
:DIAGnostic
:DISPlay
:INITiate
:OUTput
SOURce
:STATus
15
Model 845-M Programmer’s
Manual
V1.1 2011
:SYSTem
:TRIGger
:UNIT
All
Model
845-M
SCPI
commands,
exceptthe
:ABORt command,
have one or more subcommands
(keywords)
associated
with them to further define the instrument function to be
controlled.
The
subcommand
keywords may
also
have one or more
associated subcommands
(keywords).Each
subcommand
level
adds
another layer to the
command
tree. The
command
keyword and its
associated
s
ubcommand
keywords form a portion of the
command
tree
called
a command subsystem.
Status SystemProgramming
The
Model
845-M
implements
the
status
byte
register,
the
Service Request Enable Register,
the
Standard
Event
Status Register,
and the
Standard
Event
Statu
s
Enable
Register.
The
Model
845-M
status system consists
of the following
SCPI-defined status
reporting structures:
x The Instrument
Summary Status
Byte
x The
Standard
Event
Status
Group
x The Operation
Status
Group
x The
Questionable Status
Group
Thefollowing
paragraph
s
describe
the
registers
that make up a
status
group and explain
the
status
information that
each status
group provides.
Status Registers
In general, a
status
group
consists
of a
condition register,
a transition filter, an event register, and an
enable
register. Each component is
briefly
described
in the following
paragraph
s
.
ConditionRegister
The
condition register is continuously
updated to reflect the
c
u
rrent
status
of the
Model
845-M
.
There
is
no
latching
or buffering for this
register,
it
is
updated in real time.
Reading
the
contents
of a
condition
register
does
not
change
its contents.
16
Model 845-M Programmer’s
Manual
V1.1 2011
Transition
Filter
The transition filter
is
a
special register
that
specifies
which types of bit state
changes
in
the
condition
register
will set
corresponding
bits in the event
register.
Negative transition filters
(NTR)
are
used
to
detect
condition changes
from True
(1)
to
False
(0);
positive
transition filters
(PTR)
are
used
to detect
c
o
ndition
changes
from
False
(0) to True
(1).
Setting both positiveand negative filters Trueallows an
event to be reported anytime the
condition changes.
Transition filters are read-write.
Transition
filters
are
unaffe
c
ted
by
queries
or
*CLS (clear status)
and *RST
commands.
The
command
:STATus:PRESet sets
all
negative transition filters to all 0’sand
sets
all
positive
transition filters to all
1’s.
EventRegister
The event register
latches
transition events from the
condition register as specified
by
t
he
transition
filter.
Bits
in the event registerare
latched,
and
once
setthey remain setuntil cleared by a query or a
*CLS command
Event
registers
are read only.
Enable
Register
The enable
register specifies
the bits in the event
register
that
can produce
a
summary
bit. The
Model
845-M
logically ANDs corresponding
bitsin the event and enable
registers,
and
ORs
all
the
resulting
bitsto obtain a
summary
bit.
Summary
bits are
recorded
in the
Summary Status
Byte.
Enable registers
are read-write. Querying an enable
register does
not affect it. Thecommand
:STATus:PRESet sets
the Operation
Status Enable
register and the
Questionable Status
E
nable
register
to all 0’s.
Status Group
Reporting
The state of certain
Model
845-M
hardware and operational events and
condition
s
can
be
det
ermined
by
programming the
status system.
Threelower
status groups
provide
status
information to
the
Summary Status
Bytegroup. The
Summary
Statu
s
Bytegroup
is used
to determine the general nature of
an event or
condition
and the other
statu
s
groups
are
used
to determine the specific nature of the
event or condition.
Summary Status
ByteGroup
The
Summary Status
Bytegroup,
consisting
of the
Summary Status
Byte
Enable
registerand
the
Summary Status
Byte,
is used
to determine the general nature of an
Model
845-M
event or condition.
The bits in the
Summary Status
Byteprovide the
f
ollowing:
Operation
Status
Group
17
Model 845-M Programmer’s
Manual
V1.1 2011
The Operation
Status
group,
consisting
of the Operation
Condition register,
the Operation
Positive
Transition register,
the Operation Negative
Transition register,
the Operation
E
v
ent
register
and
the Operation Event
Enable
register.
Standard Event Status Group
The
Standard
Event
Status
group,
consisting
of the StandardEvent
Status
register(an Event
register)
and the StandardEvent
Status Enable register
, is used
to determine the
specific
event
that set bit 5 of
the
Summary Status
Byte.
The bits in the StandardEvent
Status
registerprovide the
following:
Bit Description
0 Setto indicatethat all pending
Model
845-M
operations
were
completed
following
execution of
the
“*OPC”
command.
1
Request
control
2 Setto indicatethat a query error
has occurred.
Query
errors
have
SCPI
error
codes
from
–499 to –400.
3 Setto indicatethat a
device-dependent
error
has
occurred.
Device-dependent errors
have
SCPI
error
codes
from –399to –300and
1
to 32767.
4 Setto indicatethat an
execution
error
has occurred. Execution errors
have
SCPI
error
codes
from
–299to –200.
5 Setto indicatethat a
command
error
has occurred. Command errors
have
SCPI
error
codes
from
–199
to –100.
6
User
request
7 Power on
Standard
Event
Status Enable
register
(ESE
commands)
Operation Status Group
The Operation
Status
group,
consisting
of the Operation
Condition register,
the Operation
Positive
Transition register,
the Operation Negative
Transition register,
the Operation
E
v
ent
register,
and the
Operation Event
Enable register, is used
to determine the
specific
condition that setbit 7in the
Summary Status
Byte.The
bit
s
in the Operation Event
register
provide
the
following:
18
Model 845-M Programmer’s
Manual
V1.1 2011
Questionable Status Group
The
Questionable Status
group,
consisting
of the
Questionable
Conditionregister,
the
Questionable
Positive Transition
regi
s
ter,
the
Que
s
tionable Negative
Transition register,
the
Questionable
Event
register,and the
Questionable
Event
Enable register, is used
to determine the
specific condition
that set
bit 3 in the
Summary Status
Byte.
19
Model 845-M Programmer’s
Manual
V1.1 2011
SCPI
Command Description
:ABORt
Subsystem
The
:ABORt command is
a
single command subsystem.
Thereare no
subcommands
or associated data
parameters, as
shown below. The
:ABORt
c
ommand,
along with the
:TRIGger
and :INITiate
commands,
comprise
the Triggergroup of commands.
Command Parameters
Unit
(defa
u
lt)
Remar
k
:ABORt V0.3.10
:ABORt
:ABORt
This command causes
the
List
or Stepsweep in
progress
to abort.
Even
if
INIT:CONT[:ALL] is
set to ON,
the sweep will not immediately
re-initiate.
20
Model 845-M Programmer’s
Manual
V1.1 2011
:DISPlay
Subsystem
The
:DISPlay subsystem controls
the
display
of the front panel data display.
Command Parameters
Unit
(defa
u
lt)
Remar
k
:DISPlay[:WINDow]:TEXT:[STATe]
ON|O
FF|1|0
V0.4.1
:DISPlay:REMote ON|OFF|1|0 V0.4.1
:DISPlay:WINDow:TEST
ON|OFF|1|0
:DISPlay[:WINDow]:TEXT:[STATe] ON|
O
FF|1|0
:DISPlay[:WINDow]:TEXT:STATe?
Turns
on/off the parameter
display
of the
Model
845-M
front panel data display.
:DISPlay:REMote
ON|OFF|1|0
:DISPlay:REMote
ON|OFF|1|0
:DISPlay:RE
Mote
?
Turns
on/off the
display
update of the
Model
845-M
front panel data display.
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