Remote Control
Copyright© Itech Electronic
Co., Ltd.
6
Message exchange protocol
Two rules summarize the message exchange protocol:
Rule 1.You must always tell the IT6500 Series what to send to the computer.
The following two steps must always be performed to send information from the
instrument other computer:
1. Send the appropriate query command(s) in a program message.1.
2. Address the IT6500 Series to talk.
Rule 2.The complete response message must be received by the computer
before another program message can be sent to the IT6500 Series.
1.6 Command Format
Formats for command display are as follows:
[SOURce[1|2]:]VOLTage:UNIT {VPP|VRMS|DBM}
[SOURce[1|2]:]FREQuency:CENTer
{<frequency>|MINimum|MAXimum|DEFault}
Based on the command syntax, most commands (and certain Parameter) are
expressed in both upper and lower cases. Upper case refers to abbreviation of
commands. Shorter program line may send commands in abbreviated format.
Long-format commands may be sent to ensure better program readability.
For example, both formats of VOLT and VOLTAGE are acceptable in the above
syntax statements. Upper or lower case may be used. Therefore, formats of
VOLTAGE, volt and Volt are all acceptable. Other formats (such as VOL and
VOLTAG) are invalid and will cause errors.
Parameter options with given command strings are included in the brace
({ }). The brace is not sent along with command strings.
Vertical stripes (|) separate several parameter options with given command
strings. For example, {VPP|VRMS|DBM} indicates that you may assign
"APP", "VRMS" or "DBM" in the above commands. Vertical stripes are not
sent along with command strings.
Angle brackets (< >) in the second example indicates that a value must be
assigned to the parameter in the brace. For example, the parameter in the
angle bracket is <frequency> in the above syntax statements. Angle
brackets are not sent along with command strings. You must assign a
value (such as "FREQ:CENT 1000") to the parameter, unless you select
other options displayed in the syntax (such as "FREQ:CENT MIN").
Some syntax elements (such as nodes and Parameter) are included in
square brackets ([ ]). It indicates that these elements can be selected and
omitted. Angle brackets are not sent along with command strings. If no
value is assigned to the optional Parameter, the instrument will select a
default value. In the above examples, "SOURce[1|2]" indicates that you
may refer to source channel 1 by "SOURce" or "SOURce1" or "SOUR1" or
"SOUR". In addition, since the whole SOURce node is optional (in the
square bracket), you can refer to the channel 1 by omitting the whole
SOURce node. It is because the channel 1 is the default channel for
SOURce language node. On the other hand, if you want to refer to channel
2, "SOURce2" or "SOUR2" must be used in the program line.
Colon (:)
It is used to separate key words of a command with the key words in next level.
