R&S FSL Status Reporting System
1300.2519.12 5.25 E-11
Application of the Status Reporting Systems
In order to be able to effectively use the status reporting system, the information contained there must
be transmitted to the controller and further processed there. There are several methods which are
represented in the following. For detailed program examples refer to chapter 7 "Remote Control –
Programming Examples".
Service Request
Under certain circumstances, the instrument can send a service request (SRQ) to the controller. Usually
this service request initiates an interrupt at the controller, to which the control program can react
appropriately. As evident from Fig. 5–4, an SRQ is always initiated if one or several of bits 2, 3, 4, 5 or 7
of the status byte are set and enabled in the SRE. Each of these bits combines the information of a
further register, the error queue or the output buffer. The ENABle parts of the status registers can be set
so that arbitrary bits in an arbitrary status register initiate an SRQ. In order to make use of the
possibilities of the service request effectively, all bits should be set to "1" in enable registers SRE and
ESE.
Example: Use of the command *OPC to generate an SRQ at the end of a sweep
1. CALL InstrWrite(analyzer, "*ESE 1") 'Set bit 0 in the ESE (Operation Complete)
2. CALL InstrWrite(analyzer, "*SRE 32") 'Set bit 5 in the SRE (ESB)?
After its settings have been completed, the instrument generates an SRQ.
The SRQ is the only possibility for the instrument to become active on its own. Each controller program
should set the instrument in a way that a service request is initiated in the case of malfunction. The
program should react appropriately to the service request. A detailed example for a service request
routine is to be found in chapter 7 "Remote Control – Programming Examples".
Serial Poll
In a serial poll, just as with command *STB, the status byte of an instrument is queried. However, the
query is realized via interface messages and is thus clearly faster. The serial–poll method has already
been defined in IEEE 488.1 and used to be the only standard possibility for different instruments to poll
the status byte. The method also works with instruments which do not adhere to SCPI or IEEE 488.2.
The VISUAL BASIC command for executing a serial poll is IBRSP(). Serial poll is mainly used to obtain
a fast overview of the state of several instruments connected to the controller.
Parallel Poll
In a parallel poll, the controller uses a single command to request up to eight instruments to transmit
one bit of information each on the data lines, i.e., to set the data line allocated to each instrument to a
logical "0" or "1". In addition to the SRE register, which determines the conditions under which an SRQ
is generated, there is a parallel poll enable register (PPE). This register is ANDed with the STB bit by bit,
considering bit 6 as well. The results are ORed, the result is possibly inverted and then sent as a
response to the parallel poll of the controller. The result can also be queried without parallel poll by
means of the command *IST?.
The instrument first has to be set for the parallel poll using the VISUAL BASIC command IBPPC().
This command allocates a data line to the instrument and determines whether the response is to be
inverted. The parallel poll itself is executed using IBRPP().
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