4 colon keyword separators, 5 command arguments and queries, 6 semicolon command separators – Boonton 4240 RF Power Meter User Manual

Page 63: 7 command terminators, 8 4240 series scpi implementation, 4 colon keyword separators -3, 5 command arguments and queries -3, 6 semicolon command separators -3, 7 command terminators -3, 8 4240 series scpi implementation -3

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Boonton 4240 Series RF Power Meter

suffix is not present, the default channel is assumed.

strument’s “Channel 1” measurement path, while SENS

For example, SENSe or SENSe1 defines operation affecting the

e2 commands will apply to channel 2.

ed si

n a filesystem. Prefixing a command string

the root c

keyword in the command. Beginning a

o t

al if the command is the first command on a

ne.

e argument. For example, “SENSe:CORRection:DCYCle 25.0” sets duty cycle

orrectio

a va

If a command requires more than one numeric

rgumen

e arg

d list.

o read

curre

rameter, the Query Form of its command may be used. A command query is

rmed

ppen

) suffix to the command instead of an argument list. There should not be any

whitespace betwe

For example, “SENSe:CORRection:DCYCle?” queries the duty cycle

correction parame

t value.

d on a line. As noted previously, the first command of a line is always referenced

the root level whether or not the command is prefixed by a colon. However, for the second and succeeding commands, the

arsing level is NOT reset to the root level, but rather referenced from the current node. This allows the parser to remain at

her commands from that node without resending the entire node string. For example, the

llowing multi-command strings are equivalent:

tion

he SCPI Model of the 4240 provides a single or dual SENSe sub-system to handle sensor input and a matching single or

ual CALCulate sub-system to process the data obtained from the sensors into useful results. The CALibration sub-system is

d to calibrate power sensors. Channel dependent commands end with a number to indicate the desired channel as follows:

in

.3.4 Colon Keyword Separators

5

The colon (“:”) character is us

milar to the way a slash or backslash is used i

with a colon resets parsing at

ommand level, and a colon must separate each

new line always resets parsing t he root level, so the leading colon is option
li

5.3.5 Command Arguments and Queries

Many commands require arguments. In this case, the entire command string is sent, followed by the argument. A space is
used to separate the command from th
c

n to

lue of 25.0. Arguments may be numeric, or alphanumeric.

a

t, th

uments must be sent as a comma delimite

T

the

nt value of a particular pa

fo

by a

ding a question-mark (“?”

en the command and the suffix.
ter, and causes the instrument to return its curren

5.3.6 Semicolon Command Separators

The semicolon (“;”) character is used to separate multiple commands on a single line. However, the parsing path is affected
when more than one command is combine
to
p
the current node, and execute ot
fo

:SENSe:CORRection:DCYCle 25.0; :SENSe:CORRection:CALFactor 2.12;

(two full-path commands)

:SENSe:CORRection:DCYCle 25.0; CALFactor 2.12;

( second command referenced to CORRection node)

SENSe:CORRection:DCYCle 25.0; CALFactor 2.12;

(leading colon omitted from first command)

If a command does not belong to the same subsystem as the preceding command on the same line, then its full path must be
specified, including the colon prefix.

5.3.7 Command Terminators

All SCPI command strings transmitted to the instrument must be terminated. For commands sent via the GPIB bus, any
character with the IEEE488 EOI (End-Or-Identify) control line asserted may be used as a terminator. This may be the last
letter of the command, query or argument. Optionally, a CR (ASCII 13) and/or LF (ASCII 10) may be included.

For commands sent via the RS-232 interface a CR and/or LF must be included to match the desired protocol.

When the terminating condition is met, the SCPI path is first reset to the root level, and the received message is then passed
to the SCPI parser for evaluation.

5.3.8 4240 Series SCPI Implementa

T
d
use

Remote Operation

5-3

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