10-2
IM 755601-01E
Response Messages
The response message format is shown below.
<RMT>
;
<Response message unit>
<Response message unit>
A response message consists of one or more
response message units; each response message unit
corresponds to one response.
Response message units are separated by a
semicolon (;).
For details regarding the format of the response
message unit, see the section “Response message
unit format.”
Unit
Unit
:CHECK:MODE BEFORE;LEVEL 5<RMT>
<RMT>
<RMT> is a response message terminator. It is
NL^END.
Response message unit format
The response message unit format is shown below.
,
<Response header>
<Response data>
Space
<Response header>
A response header sometimes precedes the response
data. A space (ASCII code “20H”) separates the data
from the header. For details, see page 10-4.
<Response data>
Response data contain the content of the response. If
there are multiple sets of response data, they are
separated by commas (,). For details, see page 10-5.
Header
Data
Data
1.05<RMT> :CHECK:MODE BEFORE<RMT>
If there are multiple queries in a program message,
responses are made in the same order as the queries.
In most cases, one query returns one response
message unit, but there are a few queries that return
multiple units. The first response message unit always
corresponds to the first query, but the nth response
unit may not necessarily correspond to the nth query.
Therefore, if you want to make sure that every
response is extracted, divide the program messages
into individual messages.
Precautions to be Taken When Transferring
Messages
• If a program message that does not contain a query
is sent, the next program message can be sent at
any time.
• If a program message that does contain a query is
sent, a response message must be received before
the next program message can be sent. If the next
program message is sent before the response
message is received in its entirety, an error occurs.
The response message that was not received is
discarded.
• If the controller tries to receive a response message
when there is none, an error occurs. If the controller
tries to receive a response message before the
transmission of the program message is complete,
an error occurs.
• If a program message containing multiple message
units is sent, and the message contains incomplete
units, the instrument will attempt to execute the ones
that are believed to be complete. However, these
attempts may not always be successful. In addition,
if the message contains queries, the responses may
not be returned.
Deadlock
The instrument can store in its buffer program and
response messages of length 1024 bytes or more (The
number of available bytes varies depending on the
operating conditions). When both the transmit and
receive buffers become full at the same time, the
instrument can no longer continue to operate. This
state is called a deadlock. In this case, operation can
be resumed by discarding the program message.
Deadlock will not occur if the program message
(including the <PMT>) is kept below 1024 bytes.
Furthermore, deadlock never occurs if a program
message does not contain a query.
10.1 Before Programming
