R3267 Series Spectrum Analyzer Operation Manual (Vol.1)
5.2.4 Responses to Interface Messages
5-10
5.2.4
Responses to Interface Messages
The IEEE Standard 488.1-1978 defines how the analyzer responds to interface messages. The responses
are described in this section.
For information on how to send interface messages to the analyzer, refer to the instruction manual of the
controller you are using.
(1)
Interface Clear (IFC)
The IFC message is transmitted directly to the analyzer through a signal line. The message allows
the analyzer to stop the operation of the GPIB bus. Although all input/output operation is stopped,
the input/output buffer is not cleared. Note that the DCL is used to clear the buffer.
(2)
Remote Enable (REN)
The REN message is transmitted directly to the analyzer through a signal line. If the analyzer is spec-
ified as a listener when the message is true, the analyzer is in remote mode. The analyzer remains in
remote mode until the GTL message is received, REN becomes false, or you press the LOCAL key.
When the analyzer is in local mode, it ignores all received data, and key inputs (except for LOCAL
key input) and when the analyzer is in LOCAL LOCKOUT mode, it ignores all key input.
(3)
Serial Polling Enable (SPE)
When the analyzer is receiving a message from an external device, it is in serial polling mode. If the
analyzer is specified as a talker in this mode, it sends status bytes instead of normal messages. the
analyzer remains in the serial polling mode until the SPD (Serial Polling Disable) message or the
IFC message is received.
When the analyzer sends an SRQ (Service Request) message to the controller, bit 6 (RQS bit) of the
response data is set to 1 (true). When the analyzer has finished sending this message, the RQS bit
reverts to 0 (false). The SRQ message is sent directly through a signal line.
(4)
Device Clear (DCL)
When the analyzer receives a DCL message, it performs the following actions:
•
Clears the input and output buffers.
•
Resets syntax analysis, execution control, and response data generation.
•
Cancels all commands that prevent the remote command from being executed next.
•
Cancels commands that are paused to wait for other parameters.
When the analyzer receives the DCL message, it does not do the following:
•
Changes data set or stored in the analyzer.
•
Interrupt front panel operation.
•
Modifie or interrupt any the analyzer operations being executed.
•
Change any status bytes other than MAV (MAV becomes 0 when the output buffer is cleared).
