Measurement Event Synchronization

Last updated: December 3, 2008

Description

Measurement event synchronization saves time by controlling the communication between the controller, the test set, and the mobile station, so that no device does something before it is supposed to (which can cause errors or do something well after it could have). Because some measurements can run concurrently, it is necessary that the control program know when individual measurement results are available.

Measurement event synchronization is accomplished using the INITiate subsystem's command INITiate:DONE? or the STATus:OPERation:NMRReady status registers.

INITiate:DONE?

The INITiate:DONE? query returns a string that indicates what, if any, measurements are ready to be fetched. This query should be used inside a loop, checking each measurement that was initiated. See INITiate:DONE? for more details about this query.

The INITiate:DONE? query returns at least one of the following indicators for each pass through the loop:

"AAUD*" - The analog audio measurement results are available.*
"BERR" - The GSM bit error measurement results are available.*
"BFI+" - The GSM bad frame indication measurement results are available.*
"BLERo" - The block error measurement results are available.o
"DAUD" - The decoded audio measurement results are available.*
"DPOW" - The dynamic power measurement results are available.
"EMACo*" - The EGPRS modulation accuracy measurement results are available.
"ETXPo*" - The EGPRS transmit power measurement results are available.*o
"FBER*" - The fast bit error measurement results are available.
"FFER+" - The frame erasure rate measurement results are available.
"GBERo" - The GPRS/EGPRS bit error measurement results are available.o
"IQT" - The I/Q Tuning measurement results are available.
"MTA*" - The multi-tone audio measurement results are available.
"ORFS" - The output RF spectrum measurement results are available.
"PFER" - The phase and frequency error measurement results are available.
"PVT" - The power versus time measurement results are available.
"SMON" - The spectrum monitor measurement results are available.
"TXP" - The GSM/GPRS transmit power measurement results are available.
"WAIT" - There are one or more measurements which are in the measuring state which are not excluded from the query. See INITiate:DONE:FLAG:<measurement mnemonic> . When WAIT is returned at least one measurement is not ready to be fetched yet.
"NONE" - There are no measurements currently in the measuring state. This assumes no measurements have been excluded. See INITiate:DONE:FLAG:<measurement mnemonic> . This indicates that all measurements results are available or none have been initiated.

The indicators marked with a o are not returned for GSM as those measurements are not available in that test application.

The indicators marked with a * are not returned for GPRS as those measurements are not available in that test application.

The indicators marked with a + are only returned for the GSM/GPRS and EGPRS lab applications.

Programming Example

The following example assumes that a call is currently connected and that no measurements other than TX power (TXP) and phase and frequency error (PFER) are currently being triggered. See Establishing an Active GSM Link with the Mobile Station and Triggering Process Description .

 
10  OUTPUT 714;"SETUP:TXPOWER:CONTINUOUS OFF" !Sets TX power trigger mode
20                                            !to single.
30  OUTPUT 714;"SETUP:PFERROR:CONTINUOUS OFF" !Sets PFER trigger mode
40                                            !to single.
50  OUTPUT 714;"INITiate:TXPower;PFERror" !Begins a TX power and
60                                        !PFER measurement.
70  REPEAT
80  OUTPUT 714;"INITIATE:DONE?" !Queries the test set for measurements
90                              !that are done
100 ENTER 714;Meas_done$ !String value representing DONE measurements,
110                      ! NONE if no measurements are done.
120 SELECT Meas_done$ !This variable will be set to WAIT until measurements
130                   !are DONE.
140 CASE "TXP" !Characters must be upper case.
150 OUTPUT 714;"FETCH:TXPOWER:POWER?" !If this case is selected, Tx power
160                                   !(no integrity indicator) is FETCHed.
170 ENTER 714;Tx_power
180 PRINT "TX_Power is ";Tx_power
190 CASE "PFER" !Characters must be uppercase.
200 OUTPUT 714;"FETCH:PFERROR:RMS?" !If this case is selected, rms phase error
210                                 !measurement is FETCHed.
220 ENTER 714;Phs_error
230 PRINT "Max RMS Phase Error is ";Phs_error
240 END SELECT
250 UNTIL Meas_done$ = "NONE" !When all triggered measurements have completed,
260                           !the INITiate:DONE? query returns NONE.
270 END

STATUS:OPERATION:NMRREADY:GSM

The STATus:OPERation:NMRReady:GSM command allows the program to immediately branch to the next operation or command without continuing through a loop as in INITiate:DONE? See STATus:OPERation:NMRReady:GSM Condition Register Bit Assignment for more details about this command.

You must enable the following so that as soon as the enabled NMRReady bit is true the program moves on.

Positive or negative transition filter. See Transition Filters .
STATus:OPERation:NMRReady:GSM bit for the measurement desired.
STATus:OPERation:NMRReady bit (4 for GSM) for the required system. See STATus Subsystem Description or Status Subsystem Overview .
STATus:OPERation bit (512 for NMRReady).
Service Request Enabling (*SRE 128 for NMRReady).

The STATus:OPERation:NMRReady:GSM Condition Register Bit Assignment status register provides status reporting on the following measurement completions:

GSM Frame Erasure Rate on the FACCH
GSM Bad Frame Indication
TX Power
Power vs. Time
Phase/Frequency Error
Output RF Spectrum
Analog Audio
Decoded Audio
Fast Bit Error Rate
Bit Error Rate
I/Q Tuning
Dynamic Power

Generating a Service Request (SRQ) Interrupt - Bit Error Rate NMRR

The following example illustrates the use of the STATus subsystem to generate a service request when a BERR measurement completes. This example assumes a call is already connected and the BERR measurement is setup (mobile station must be in loopback type A or B).

 
10  OUTPUT 714;"STATUS:OPERATION:NMRREADY:GSM:PTR 256" !Enable positive transition
20                                                 !filter on fast BER bit.
30  OUTPUT 714;"STATUS:OPERATION:NMRREADY:GSM:ENABLE 256" !Enable the fast BER Bit to
40                                                    !generate a summary message.
45  OUTPUT 714;"STATUS:OPERATION:NMRREADY:ENABLE 4" !Enable the GSM summary bit.
50  OUTPUT 714;"STATUS:OPERATION:ENABLE 512" !Enable the Operation summary bit to
60                                           !generate a summary message.
70  OUTPUT 714;"*SRE 128" !Enable the service request enable register to generate SRQ.
80  OUTPUT 714;"*CLS" !Clear all status data structures.
90  ON INTR 7,15 CALL Meas_complete !Define interrupt-initiated branch with a priority
100                                 !of 15 (highest)
110 ENABLE INTR 7;2 !Enable interrupt on interface card 7 with a bit mask
120                 !(for interface's interrupt-enable register) of 2.
130 OUTPUT 714;"SETUP:FBER:CONTINUOUS OFF;:INITIATE:FBERROR" !Initiate a single
140                                                          !fast BER test.
150 LOOP
160 DISP "Waiting for BERR test to complete"
170 WAIT .1 !"Dummy" loop
180 END LOOP
190 !Instead of a "dummy" loop, controlling application could be performing setups,
200 !making measurements, etc.
210 END
220 SUB Meas_complete
230 DISP "BER test complete, OK to FETCh results now"
240 Clear_interrupt=SPOLL(714) !Clear the RQS message in the status byte register.
250 STOP
260 SUBEND

Operating Considerations

Only one indicator is returned per query.

All active measurements must be set to single trigger mode. This ensures that when a measurement completes it remains in the "DONE" state rather than restarting. Sending the "*RST" command at the beginning of the test code or using the "SETup:CONTinous:OFF" command during measurement setups are ways to set the trigger to single for all measurements.