Other topics about Application Programs
The pow_cal.vba shows a sample program (VBA program) for executing power calibration using the E4418B power meter and the E4412A power sensor. This VBA program consists of the following modules:
|
Object name |
Module type |
Description |
|
mdlPowCal |
Standard module |
Executes power calibration |
|
Module1 |
Standard module |
Definition files for using VISA library |
The program connects the E5071C and the E4418B (GPIB address: 13) through the USB/GPIB interface as shown below. Then, the program executes the zero adjustment and calibration of the power sensor (E4412A) connected to the power meter (E4418B) as necessary. Finally, it executes the power calibration of the E5071C and saves the obtained power calibration data array into a file.
Connection between E5071C and power meter
When you run this VBA program, reset is performed, the GPIB address of the power meter to be controlled and the measurement conditions of the E5071C are set, and the message "Do you want to zero and calibrate the power sensor?" is displayed. If you want to execute the zero adjustment and the calibration of the power sensor, click Yes, otherwise click No.
If you want to execute the zero adjustment and calibration of the power sensor, follow the displayed messages to connect the power sensor connected to the A channel of the power meter to the POWER RF port of the power meter and click OK. When the zero adjustment and calibration of the power sensor is complete, the message "Zeroing and calibrating the power sensor is complete" is displayed.
When a message that prompts you to connect the power sensor to port 1 of the E5071C is displayed, make the connection and then click OK. The power calibration data measurement is executed immediately and the obtained power calibration data array is saved in a file named CORR_DATA.
The power calibration execution program (object name: mdlPowCal) is described in detail below. Line numbers are added for description purpose only and do not appear in the actual program source code.
Assign the sweep type (power sweep), the number of points (41), the power range (-20 to +12 dBm), the sweep start value (-20 dBm), the sweep stop value (-10 dBm), and the fixed frequency (1 GHz) to the Swp_type, Nop, Pow_rang, Start_p, Stop_p, and Cw_freq variables, respectively.
Assign the number of power calibration data measurements for each measurement point (4) and the limit value of the power calibration data array (10 dBm) into the Num_avg and Limit variables, respectively.
Returns the E5071C to the preset state.
Sets the power meter's GPIB address (13) in the E5071C.
For channel 1, these lines assign the sweep type to the Swp_type variable, the number of points to the Nop variable, the power range to the Pow_rang variable, the sweep start value to the Start_p variable, the sweep stop value to the Stop_p variable, and the fixed frequency to the Cw_freq variable.
Display a message asking whether to execute the zero adjustment and calibration of the power sensor. If the Yes button is clicked, these lines call the procedure: Control_PowerMeter (Line 900 to Line 1340). On the other hand, if the No button is clicked, the program skips the zero adjustment and calibration of the power sensor.
Clear the error queue. Then, these lines prompt you to connect the power sensor to port 1 of the E5071C and wait for the OK button to be clicked after the connection.
For port 1 of channel 1, these lines set the number of power calibration data measurements for each measurement point to the Num_avg variable and then start the measurement of the power calibration data and wait for the completion of the measurement.
Reads out an error that has occurred in the E5071C during the measurement of the power calibration data and sets it in the Err variable.
If no error has occurred, these lines read out the power calibration data array and set it in the Corr_data variable. In addition, the program uses the Limit_Test function to check whether the read out power calibration data array exceeds the specified limit value. If the limit value is exceeded, the return value of the Limit_Test function, False, is returned. Then, a message is displayed asking whether to perform the power calibration again. Click the Yes button to return to the start of the power calibration data measurement. Click the No button to terminate the program.
If an error occurs, display an error message and a message asking whether to execute the power calibration again. Click the Yes button to return to the start of the power calibration data measurement. Click the No button to terminate the program.
Write the read out power calibration data array into a file named CORR_DATA. Then, these lines display a message that saving into a file has been successfully completed.
Initialize and start up the VISA system and output the startup information to the Defrm variable. During this process, if an error occurs, the program goes to the error handling routine (Lines 1260 to 1300).
Establish the connection to the power meter in use (GPIB address: 13) and output the connection information to the E4418 variable. During this process, if an error occurs, the program goes to the error handling routine (Lines 1260 to 1300).
Return the power meter to the preset state through VISA and clear the status byte register and the standard event status register. Then, these lines enable the standard event status register's bit 0.
Prompts you to connect the power sensor to the POWER REF port of the power meter and waits for the OK button to be clicked after the connection.
Execute the zero adjustment and calibration of the power sensor through VISA. These lines make the setting so that 1 is set to bit 0 of the standard event status register when all pending operations are completed.
Retrieve the value of the status byte register through VISA and set it into the Rgst variable. These lines set the AND of the read-out value and 32 (the value in which only bit 5 is 1) into the Rslt variable and display a message that the zero adjustment and calibration of the power sensor is completed when Rslt becomes 1 (when the zero adjustment and calibration of the power sensor is completed).
Breaks the communication and terminates the VISA system.
If an error occurs in a VISA function, these lines display the details of the error and terminate the program.
If the absolute value of the read out power calibration data array exceeds the specified limit value, these lines turn off the power calibration function and return the value of False. Otherwise, the value of True is returned.
Measurement of power calibration (object name: mdlPowCal)
10| Sub Main()
20|
30| Dim Swp_type As String, File As String
40| Dim Start_p As Double, Stop_p As Double, Cw_freq As Double, Limi t As Double
50| Dim Nop As Long, Pow_rang As Long, Num_avg As Long, Data_size As Long, Buff As Long, Dmy As Long
60| Dim Corr_data As Variant, Err As Variant
70| Dim Verifier As Boolean
80| Dim FileNo As Integer, I As Integer
90|
100| Swp_type = "POW" 'Sweep type : POWER
110| Nop = 41 'Number of points : 41
120| Pow_rang = 0 'Power range : -20 to +12 dBm
130| Start_p = -20# 'Start power : -20 dBm
140| Stop_p = -10# 'Stop power : -10 dBm
150| Cw_freq = 1000000000# 'CW frequency : 1 GHz
160| Num_avg = 4 'Number of averaging : 4
170| Limit = 10# 'limit for corrected data : 10 dBm
180|
190| '''Presetting the ENA
200| SCPI.SYSTem.PRESet
210|
220| '''Setting GPIB address of the power meter to ENA
230| SCPI.SYSTem.COMMunicate.GPIB.PMETer.address = 13
240|
250| '''Setting measurement conditions
260| SCPI.SENSe(1).SWEep.TYPE = Swp_type
270| SCPI.SENSe(1).SWEep.POINts = Nop
280| SCPI.Source(1).POWer.ATTenuation.DATA = Pow_rang
290| SCPI.Source(1).POWer.STARt = Start_p
300| SCPI.Source(1).POWer.STOP = Stop_p
310| SCPI.SENSe(1).FREQuency.CW = Cw_freq
320|
330| '''Performing a calibration in the power meter
340| Buff = MsgBox("Do you perform zeroing and calibrating the power sensor?", vbYesNo, "Power meter calibration")
350| If Buff = vbYes Then
360| Control_PowerMeter
370| End If
380|
390| Meas_Start:
400| '''Connecting the power sensor to the port 1 in the ENA
410| SCPI.IEEE4882.CLS
420| MsgBox "Set the power sensor connected to the port 1 in the ENA.", vbOKOnly, "Power meter calibration"
430|
440| '''Performing power calibration measurement
450| SCPI.Source(1).POWer.PORT(1).CORRection.COLLect.AVERage.count = Num_avg
460| SCPI.Source(1).POWer.PORT(1).CORRection.COLLect.ACQuire = "ASEN "
470| Dmy = SCPI.IEEE4882.OPC
480|
490| '''Error handling at power meter calibration
500| Err = SCPI.SYSTem.Error
510| If Err(0) = 0 Then
520| Corr_data = SCPI.Source(1).POWer.PORT(1).CORRection.DATA
530| Verifier = Limit_Test(Nop, Limit, Corr_data)
540| If Verifier = False Then
550| Buff = MsgBox("Do you perform the power meter calibration me asurement again?", vbYesNo, "Power meter calibration")
560| If Buff = vbYes Then GoTo Meas_Start
570| If Buff = vbNo Then GoTo Prog_Stop
580| End If
590| MsgBox "Power meter calibration measurement is complete.", vbO KOnly, "Power meter calibration"
600|
610| Else
620| MsgBox "Error: " & Err(1)
630| Buff = MsgBox("Do you perform the power meter calibration meas urement again?", vbYesNo, "Power meter calibration")
640| If Buff = vbYes Then GoTo Meas_Start
650| If Buff = vbNo Then GoTo Prog_Stop
660| End If
670|
680| '''Installing the corrected data to a file
690| FileNo = FreeFile
700| File = "CORR_DATA"
710|
720| Open File For Output As FileNo
730|
740| For I = 0 To Nop - 1
750| Write #FileNo, Val(Corr_data(I))
760| Next I
770| Close #FileNo
780|
790| MsgBox "Installing the corrected data to the file is DONE.", vbO KOnly, "Power meter calibration"
800|
810| GoTo Prog_End
820|
830| Prog_Stop:
840| MsgBox "Program Interruption", vbOKOnly, "Power meter calibratio n"
850|
860| Prog_End:
870|
880| End Sub
890|
900| Private Sub Control_PowerMeter()
910|
920| Dim Status As Long 'VISA function status return
930| Dim Defrm As Long 'Session to default resource code
940| Dim E4418 As Long 'Session to power meter
950| Dim Rslt As Integer
960| Dim Rgst As String * 10
970|
980| '''Initializing the VISA system
990| Status = viOpenDefaultRM(Defrm)
1000| If (Status <> VI_SUCCESS) Then GoTo VisaErrorHandler
1010|
1020| '''Opening the session to the power meter
1030| Status = viOpen(Defrm, "GPIB0::13::INSTR", 0, 0, E4418)
1040| If (Status <> VI_SUCCESS) Then GoTo VisaErrorHandler
1050|
1060| '''Zeroing and calibratingthe power meter
1070| Status = viVPrintf(E4418, "SYST:PRES" & Chr$(10), 0)
1080| Status = viVPrintf(E4418, "*CLS" & Chr$(10), 0)
1090| Status = viVPrintf(E4418, "*ESE 1" & Chr$(10), 0)
1100| MsgBox "Set the power sensor connected to the POWER REF port in the power meter.", vbOKOnly, "Power meter calibration"
1110| Status = viVPrintf(E4418, "CAL1:ALL" & Chr$(10), 0)
1120| Status = viVPrintf(E4418, "*OPC" & Chr$(10), 0)
1130| Do While Rslt = 0
1140| Status = viVPrintf(E4418, "*STB?" & Chr$(10), 0)
1150| Status = viVScanf(E4418, "%t", Rgst)
1160| Rslt = CInt(CInt(Rgst) And 32)
1170| Loop
1180|
1190| MsgBox "Zeroing and Calibrating the power sensor is complete.", vbOKOnly, "Power meter calibration"
1200|
1210| '''Closing the resource manager session
1220| Call viClose(Defrm)
1230|
1240| GoTo Prog_End
1250|
1260| VisaErrorHandler:
1270| Dim VisaErr As String * 200
1280| Call viStatusDesc(Defrm, Status, VisaErr)
1290| MsgBox "Error : " & VisaErr, vbExclamation
1300| End
1310|
1320| Prog_End:
1330|
1340| End Sub
1350|
1360| Function Limit_Test(Nop As Long, Limit As Double, Corr_data As Var iant) As Boolean
1370|
1380| Dim I As Integer
1390|
1400| For I = 0 To Nop - 1
1410|
1420| If Abs(Corr_data(I)) > Limit Then
1430| SCPI.Source(1).POWer.PORT(1).CORRection.STATe = False
1440| MsgBox "The corrected data is out of limit!", vbExclamation, "Power meter calibration"
1450| Limit_Test = False
1460| Exit Function
1470| End If
1480|
1490| Next I
1500|
1510| Limit_Test = True
1520|
1530| End Function