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2.1 Messages
Response Messages
The data returned by this instrument to the controller is
called a response message. The format of a response
message is shown below.
;
<Response message unit>
<Response message units>
A response message consists of one or more
response message units: each response message unit
corresponds to one response.
Response message units are delimited by a [
For the response message format, refer to the next
page.
Example
:SAMPLE:GATE:MODE EXTERNAL;POLARITY POSITIVE<RMT>
Unit
<RMT>
RMT is the terminator used for every response
message. Only one type of response message is
available;
NL^END
.
Response message unit format
The format of a program message unit is shown below.
<Rsps. header>
Space
<Response header>
A response header sometimes precedes the response
data. Response data must be separated from the
header by a space. For details, refer to page 2-4.
<Response data>
Response data is used to define a response. If multiple
items of response data are used, they must be
separated by a
","
(comma). For details, refer to page
2-5.
Example
500.0E-03<RMT> :SAMPLE:INTERVAL MINIMUM<RMT>
Data
Header
2-2
<RMT>
;
].
Unit
,
<Response data>
Data
If a program message contains more than one query,
responses are made in the same order as the queries.
Normally, each query returns only one response
message unit, but there are some queries which return
more than one response message unit. The first
response message unit always responds to the first
query, but it is not always true that the
always responds to the
want to make sure that a response is made to each
query, the program message must be divided up into
individual messages.
Points to Note concerning Message Transmission
• It is always possible to send a program message if
the previous message which was sent did not
contain any queries.
• If the previous message contained a query, it is not
possible to send another program message until a
response message has been received. An error will
occur if a program message is sent before a
response message has been received in its entirety.
A response message which has not been received
will be discarded.
• If an attempt is made by the controller to receive a
response message, even if there it no response
message, an error will occur. An error will also occur
if the controller makes an attempt to receive a
response message before transmission of a
program message has been completed.
• If a program message of more than one unit is sent
and some of the units are incomplete, this
instrument receives program message units which
the instrument thinks complete and attempts to
execute them. However, these attempts may not
always be successful and a response may not
always be returned, even if the program message
contains queries.
Dead Lock
This instrument has a buffer memory in which both
program and response messages of 1024 bytes or
more can be stored. (The number of bytes available
will vary depending on the operating state of the
instrument.) If both buffer memories become full at the
same time, this instrument becomes inoperative. This
state is called dead lock. In this case, operation can be
resumed by discarding the response message.
No dead lock will occur, if the size of the program
message including the PMT is kept below 1024 bytes.
Furthermore, no dead lock will occur if the program
message does not contain a query.
'
n
'
th unit
'
n
'
th query. Therefore, if you
IM 704310-12E
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