Search Results for 'api'

[Andrew]

Hello Catalin,

Check out your other thread for my response to the 2 streaming receiver question.

As for performance regressions. I am re-visiting this issue for a short time. As we have discussed in earlier emails, the bbGetIQ function adds a small amount of additional overhead. At this point I have only seen a marginal regression on one Win10 laptop in our office. All other PCs I have tested exhibit a non-observable CPU increase by switching to the bbGetIQ functionality. In the latest 3.0.14 API, the bbFetchRaw function is simply routed to the bbGetIQ function, and will incur the small overhead.

I will use the Win10 laptop as a test bed for some potential optimizations.

In the mean-time, as we previously discussed, you can continue to use the 3.0.11 API version and the bbFetchRaw functionality.

Regards,
A.J.

[subscr]

Hi catalin_ro,

I am facing the same issues too with the new API and BB60C in a multi-instrument configuration. The older API has been more well behaved.

Infact, we had almost placed an order for several pairs of BB60C for a similar requirement. But now I think it will be worthwhile to wait and see if “multiple BB60C on the same host” issue can be resolved by Signal Hound.

To me it looks like an minor API issue. I hope it is taken care of soon.

rgds

Hello,

With the APIs that came after v3.0.11 there is a serious performance hit in zero-span mode, especially when using two BB60C simultaneously (Spike used for both of them). The test PCs are roughly equivalent – i7-2600/16GB/Radeon HD6850 and i7-4710HQ/16GB/nVidia.

Spike 3.0.21 (with API 3.0.11) shows about 10% CPU usage per receiver (so 20% total CPU usage when using both of them) when not decimating (27MHz BW/40MHz sampling rate).

Starting with Spike 3.0.22 (API 3.0.12 and newer) shows about 15% CPU usage for the same settings, but the total CPU usage jumps to 60% when using both receivers. Those 60% are equally split between the two Spike instances.

The test PCs are running Windows 10 Home, 64-bit, fully updated, including the newest drivers.

Regards, Catalin

Hello,

While trying to use two BB60C in the same Windows application, in IQ streaming mode, only the samples from the first started device are received. bbInitiate returns no error code, but neither bbGetIQ nor bbFetchRaw return any data or any error code for the second started device.
The test was done using API versions 3.0.11 and 3.0.14.

The same test on Linux, with API version 3.0.11, has the same end result. Even worse, on Linux even if used in separate applications the second started BB60C returns no IQ samples.

Any chance to get this fixed?

Regards, Catalin

[Andrew]

Hello sszqdz,

If you are happy with version API 3.0.6, you can get this by installing version 3.0.11 of Spike from the link below.

https://signalhound.com/sigdownloads/Spike/Spike(x64)_3011.zip

Once installed you can find the API in the installation directory.
If you have a newer version of Spike installed, you will need to manually uninstall it before 3.0.11 will install.

Hope this helps,

Regards,
A.J.

Hello,everyone
I wrote a program which use bb_api.dll.
My program crashed when I use the bb_api.dll of v3.0.13/3.0.14,but it ran well with v3.0.5.
So I want old dll between 3.0.6 to 3.0.12 to test.
So …can you help me ? Thanks~

[Anonymous]

Hi Art!

The example in the folder you download has no problem.
The problem I met is I want to get IQ data.
There is no this example.
So we have to build the VI our self with the getIQ data API.
I already wrote it, but I think something wrong.
It crash all the time when the API getIQ was called.
Do you need my VI? I can send to you.

[Andrew]

Hello akarthikeyan,

I apologize, I don’t have much experience with ctypes or Python but I can try to help.

It doesn’t look like you are creating a proper array to pass to our API. This line right here

min = ct.c_double(swlen.value)

It looks like you are simply create a single double, whereas you need an array of doubles. (This is an educated guess on my part)

Also, if you are calling GetSweep, you do not need to call GetPartialSweep. Unless you have specific reason to, you will only need GetSweep. GetPartialSweep is a method for retrieving a very long sweep as it is updating. You should start with simply GetSweep for now until you need this functionality.

There might be others who can be of further assistance.

Regards,
A.J.

Hi,

I am trying to do a sweep using sa_api.dll and python & ctypes and I am getting an error and python is getting killed when I call ‘saGetSweep’ function. Following is my program and error.

+++++++
Snippet
+++++++
import os
import sys
import ctypes as ct

class SA124B():
def __init__(self):
self.dllpath = os.path.join(os.getcwd(), ‘x64/sa_api.dll’)
self.sa = 0
self.deviceHandle = 0

# Initialize
self.sa = ct.CDLL(self.dllpath)
print “Successfuly Initialized”

# Open Device
def openDevice(self):
self.deviceHandle = ct.c_int(0)
deviceHandlePnt = ct.pointer(self.deviceHandle)
res = self.sa.saOpenDevice(deviceHandlePnt)
if res == 0:
print ‘Opened Device Successfully’
else:
print “Opening Device Failed”
sys.exit(0)

# Get Serial Number
def getSerialNumber(self):
serialNo = ct.c_uint(0)
serialNoPnt = ct.pointer(serialNo)
self.sa.saGetSerialNumber(self.deviceHandle, serialNoPnt)
print ‘Serial Number: %s’ % str(serialNo.value)

# Get Firmware Vesion
def getFirmwareVersion(self):
firmwareRev = ct.c_uint(0)
firmwareRevPnt = ct.pointer(firmwareRev)
self.sa.saGetFirmwareString(self.deviceHandle, firmwareRevPnt)
print ‘Firmware Revision: %s’ % str(firmwareRev.value)

# Get Device Type
def getDeviceType(self):
devType = ct.c_uint(0)
devTypePnt = ct.pointer(devType)
self.sa.saGetDeviceType(self.deviceHandle, devTypePnt)
print ‘Device Type: %s’ % str(devType.value)

# Get API Version
def getAPIVersion(self):
self.sa.saGetAPIVersion.restype = ct.c_char_p # Tell ctypes this function returns a pointer to a string
apiRevStr = self.sa.saGetAPIVersion(self.deviceHandle)
ret = ct.c_char_p(apiRevStr).value # Dereference pointer, extract string
print ‘API Version: %s’ % str(ret)

# Configure Center Span
def cfgCeterSpan(self):
center = ct.c_double(915.0e6)
span = ct.c_double(1.0e6)
res = self.sa.saConfigCenterSpan(self.deviceHandle, center, span)
if res == 0:
print ‘Configured Center Span’
else:
print ‘Configuring Center Span Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Acquisition
def cfgAcquisition(self):
detector = ct.c_uint(0)
scale = ct.c_uint(0)
res = self.sa.saConfigAcquisition(self.deviceHandle, detector, scale)
if res == 0:
print ‘Configured Acquisition’
else:
print ‘Configuring Acquisition Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Level
def cfgLevel(self):
ref = ct.c_double(-10.0)
atten = ct.c_double(-1)
res = self.sa.saConfigLevel(self.deviceHandle, ref, atten)
if res == 0:
print ‘Configured Level’
else:
print ‘Configuring Level Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Sweep Coupling
def cfgSweepCoupling(self):
rbw = ct.c_double(1.0e3)
vbw = ct.c_double(1.0e3)
rejection = ct.c_bool(True)
res = self.sa.saConfigSweepCoupling(self.deviceHandle, rbw, vbw, rejection)
if res == 0:
print ‘Configured Sweep Coupling’
else:
print ‘Configuring Sweep Coupling Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Initiate
def startSweep(self):
mode = ct.c_int(0)
flag = ct.c_uint(0)
res = self.sa.saInitiate(self.deviceHandle, mode, flag)
if res == 0:
print ‘Started Sweep’
else:
print ‘Start Sweep Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Get Sweep and Frame Characteristics
def getSweepInfo(self):
swlen = ct.c_int()
swlenPnt = ct.pointer(swlen)
sfreq = ct.c_double()
sfreqPnt = ct.pointer(sfreq)
binsz = ct.c_double()
binszPnt = ct.pointer(binsz)
res = self.sa.saQuerySweepInfo(self.deviceHandle, swlenPnt, sfreqPnt, binszPnt)
if res == 0:
print ‘Got Sweep Info’
print ‘Sweep Length: %s’ % str(swlen.value)
print ‘Start Frequency: %s’ % str(sfreq.value)
print ‘Bin Size: %s’ % str(binsz.value)

min = ct.c_double(swlen.value)
minPnt = ct.pointer(min)
max = ct.c_double(swlen.value)
maxPnt = ct.pointer(max)
# res = self.sa.saGetSweep_64f(self.deviceHandle, minPnt, maxPnt)
start = ct.c_int32(500)
startPnt = ct.pointer(start)
stop = ct.c_int32(1000)
stopPnt = ct.pointer(stop)
res = self.sa.saGetPartialSweep_64f(self.deviceHandle, minPnt, maxPnt, startPnt, stopPnt)
print ‘result: %s’ % str(res)
if res == 0:
print ‘Got Sweep Results’
#print minPnt
#print min.value
#print ‘Minimum Point: %s’ % str(min.value)
#print ‘Maximum Point: %s’ % str(max.value)
else:
print ‘Get Sweep Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)
else:
print ‘Querying Sweep Info Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

def Abort(self):
res = self.sa.saAbort(self.deviceHandle)
if res == 0:
print ‘Aborted’
else:
print ‘Abort Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

def closeDevice(self):
res = self.sa.saCloseDevice(self.deviceHandle)
if res == 0:
print ‘Closed Device Successfully’
else:
print ‘Closing Device Failed: %s’ % str(res)
sys.exit(0)

if __name__ == “__main__”:
sa = SA124B()
sa.openDevice()
#sa.getSerialNumber()
#sa.getFirmwareVersion()
#sa.getDeviceType()
#sa.getAPIVersion()
sa.cfgCeterSpan()
sa.cfgAcquisition()
sa.cfgLevel()
sa.cfgSweepCoupling()
sa.startSweep()
sa.getSweepInfo()
sa.getSweep()
sa.Abort()
sa.closeDevice()

+++++++++

+++++++++
ERROR
+++++++++
Please find attached Error1.png and Error2.png.
+++++++++

Attachments:

You must be logged in to view attached files.

Hi,

I am trying to do a sweep using sa_api.dll and python & ctypes and I am getting an error and python is getting killed when I call ‘saGetSweep’ function. Following is my program and error.

+++++++
Snippet
+++++++
import os
import sys
import ctypes as ct

class SA124B():
def __init__(self):
self.dllpath = os.path.join(os.getcwd(), ‘x64/sa_api.dll’)
self.sa = 0
self.deviceHandle = 0

# Initialize
self.sa = ct.CDLL(self.dllpath)
print “Successfuly Initialized”

# Open Device
def openDevice(self):
self.deviceHandle = ct.c_int(0)
deviceHandlePnt = ct.pointer(self.deviceHandle)
res = self.sa.saOpenDevice(deviceHandlePnt)
if res == 0:
print ‘Opened Device Successfully’
else:
print “Opening Device Failed”
sys.exit(0)

# Get Serial Number
def getSerialNumber(self):
serialNo = ct.c_uint(0)
serialNoPnt = ct.pointer(serialNo)
self.sa.saGetSerialNumber(self.deviceHandle, serialNoPnt)
print ‘Serial Number: %s’ % str(serialNo.value)

# Get Firmware Vesion
def getFirmwareVersion(self):
firmwareRev = ct.c_uint(0)
firmwareRevPnt = ct.pointer(firmwareRev)
self.sa.saGetFirmwareString(self.deviceHandle, firmwareRevPnt)
print ‘Firmware Revision: %s’ % str(firmwareRev.value)

# Get Device Type
def getDeviceType(self):
devType = ct.c_uint(0)
devTypePnt = ct.pointer(devType)
self.sa.saGetDeviceType(self.deviceHandle, devTypePnt)
print ‘Device Type: %s’ % str(devType.value)

# Get API Version
def getAPIVersion(self):
self.sa.saGetAPIVersion.restype = ct.c_char_p # Tell ctypes this function returns a pointer to a string
apiRevStr = self.sa.saGetAPIVersion(self.deviceHandle)
ret = ct.c_char_p(apiRevStr).value # Dereference pointer, extract string
print ‘API Version: %s’ % str(ret)

# Configure Center Span
def cfgCeterSpan(self):
center = ct.c_double(915.0e6)
span = ct.c_double(1.0e6)
res = self.sa.saConfigCenterSpan(self.deviceHandle, center, span)
if res == 0:
print ‘Configured Center Span’
else:
print ‘Configuring Center Span Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Acquisition
def cfgAcquisition(self):
detector = ct.c_uint(0)
scale = ct.c_uint(0)
res = self.sa.saConfigAcquisition(self.deviceHandle, detector, scale)
if res == 0:
print ‘Configured Acquisition’
else:
print ‘Configuring Acquisition Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Level
def cfgLevel(self):
ref = ct.c_double(-10.0)
atten = ct.c_double(-1)
res = self.sa.saConfigLevel(self.deviceHandle, ref, atten)
if res == 0:
print ‘Configured Level’
else:
print ‘Configuring Level Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Configure Sweep Coupling
def cfgSweepCoupling(self):
rbw = ct.c_double(1.0e3)
vbw = ct.c_double(1.0e3)
rejection = ct.c_bool(True)
res = self.sa.saConfigSweepCoupling(self.deviceHandle, rbw, vbw, rejection)
if res == 0:
print ‘Configured Sweep Coupling’
else:
print ‘Configuring Sweep Coupling Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Initiate
def startSweep(self):
mode = ct.c_int(0)
flag = ct.c_uint(0)
res = self.sa.saInitiate(self.deviceHandle, mode, flag)
if res == 0:
print ‘Started Sweep’
else:
print ‘Start Sweep Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

# Get Sweep and Frame Characteristics
def getSweepInfo(self):
swlen = ct.c_int()
swlenPnt = ct.pointer(swlen)
sfreq = ct.c_double()
sfreqPnt = ct.pointer(sfreq)
binsz = ct.c_double()
binszPnt = ct.pointer(binsz)
res = self.sa.saQuerySweepInfo(self.deviceHandle, swlenPnt, sfreqPnt, binszPnt)
if res == 0:
print ‘Got Sweep Info’
print ‘Sweep Length: %s’ % str(swlen.value)
print ‘Start Frequency: %s’ % str(sfreq.value)
print ‘Bin Size: %s’ % str(binsz.value)

min = ct.c_double(swlen.value)
minPnt = ct.pointer(min)
max = ct.c_double(swlen.value)
maxPnt = ct.pointer(max)
# res = self.sa.saGetSweep_64f(self.deviceHandle, minPnt, maxPnt)
start = ct.c_int32(500)
startPnt = ct.pointer(start)
stop = ct.c_int32(1000)
stopPnt = ct.pointer(stop)
res = self.sa.saGetPartialSweep_64f(self.deviceHandle, minPnt, maxPnt, startPnt, stopPnt)
print ‘result: %s’ % str(res)
if res == 0:
print ‘Got Sweep Results’
#print minPnt
#print min.value
#print ‘Minimum Point: %s’ % str(min.value)
#print ‘Maximum Point: %s’ % str(max.value)
else:
print ‘Get Sweep Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)
else:
print ‘Querying Sweep Info Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

def Abort(self):
res = self.sa.saAbort(self.deviceHandle)
if res == 0:
print ‘Aborted’
else:
print ‘Abort Failed: %s’ % str(res)
self.closeDevice()
sys.exit(0)

def closeDevice(self):
res = self.sa.saCloseDevice(self.deviceHandle)
if res == 0:
print ‘Closed Device Successfully’
else:
print ‘Closing Device Failed: %s’ % str(res)
sys.exit(0)

if __name__ == “__main__”:
sa = SA124B()
sa.openDevice()
#sa.getSerialNumber()
#sa.getFirmwareVersion()
#sa.getDeviceType()
#sa.getAPIVersion()
sa.cfgCeterSpan()
sa.cfgAcquisition()
sa.cfgLevel()
sa.cfgSweepCoupling()
sa.startSweep()
sa.getSweepInfo()
sa.getSweep()
sa.Abort()
sa.closeDevice()

+++++++++

+++++++++
ERROR
+++++++++
Please find attached Error1.png and Error2.png.
+++++++++

Attachments:

You must be logged in to view attached files.

[Anonymous]

I downloaded sa_api.dll from https://signalhound.com/support/product-downloads/sa44b-sa124b-downloads/
No error occurred when I run VI.

What error occurred? Could you show me screenshot? Sorry for my bad English

[Anonymous]

Hi Art.
I don’t have your e-mail.
I attach the sa_api.dll here, thank you so much for trying to help me.

[Anonymous]

Please, send me sa_api.dll. I’ll try to help you.

[Andrew]

Hello Randy,

Have you taken a look at the IQ examples we provide in the C programming language? They are freely available in the API download folder. These examples will show you all the functions required to configure IQ acquisition. I suggest getting the functionality to work in C before moving to Labview.

The download link for the API files is on the downloads page at,
https://signalhound.com/support/product-downloads/sa44b-sa124b-downloads/

The download also includes the API manual which will help with any questions you have while looking over the API examples.

Regards,
A.J.

[Anonymous]

Dear Andrew

Thank you for your reply!
Could you tell me how to make the API GetIQ work?
It seems doesn’t work.

Regard,
Randy

[Andrew]

Hello Randy,

I apologize, we do not have any examples for IQ acquisition in Labview. We only have the sweep example found in the API download folder and there are some sweep examples developed by customers on our forums.

Regards,
A.J.

[Andrew]

Hi Tom,

If you need time stamping from a GPS, you can accomplish this but will need to utilize the C programming interface to accomplish this. Our desktop software does not expose this functionality. If it is interesting to you, a future update to our software will allow long IQ recordings with system time stamping (non GPS). I would expect this in the coming weeks to months.

Using an external GPS and our programming interface, you can expect time stamping with a resolution of around 50ns at the highest sample rates (40MS/s IQ). There is a code example of performing this on page 45 of our programming manual, which you can find linked here,
https://signalhound.com/sigdownloads/BB60C/BB60-API-Manual.pdf
It uses a deprecated function (bbFetchRaw) which has been replaced with bbGetIQ, but otherwise would remain the same if you decided to implement this.

If you have any additional questions let me know.

Regards,
A.J.

[Justin Crooks]

Sadak,
Yes, the resolution bandwidth, or RBW, is essentially the resolution of your frequency readout. For exact frequencies we have two tools: the frequency difference meter, and the modulation analyzer in zero span.

If you are looking for precise numeric calculations on an exact frequency, I would encourage you to use our API to acquire I/Q data, which can be processed to provide whatever measurements you desire.

[Andrew]

Sadak,

There is unfortunately no way to directly pre-calculate beforehand the bin size because we create the window function at the time of saInitiate(). Other analyzers might use fixed windows and zero-padding which would allow you to pre-calculate the bin size beforehand. Depending on the RBW the window might affect the bin size between a factor of 3-6. (ie The bin size is roughly between 3 and 6 times smaller than the RBW), but again, there is no way to fully pre-calculate this value. This is why we provide the bin size with the start frequency, so you can calculate the frequency of any given bin and also target the frequency bin you are interested in with a small amount of arithmetic.

That said… if you require a sweep with a specific bin size spacing, you could convert the sweep the API returns by re-sampling the sweep at the frequencies you want. A very simple algorithm for this would be to simply select the closest bin to the frequency you desire and use this amplitude for your new bin. You would not want to ‘resample’ by a large factor, ideally you are ‘resampling’ by some small fraction to line up the bins on some frequency that is convenient for you. The flattop window would ensure that your peaks would remain. Certain measurements such as channel power might be affected but probably by negligible amounts.

Regards,
A.J.

[sadak]

Hi Andrew,

Thanks for the quick reply! Thanks for reminding that the window function also plays an important role in it. I’m quite new in this spectrum analyser stuff, my initial thought would be that the bin size is the same as rbw but apparently, it’s not.

It still makes sense to me that the bin size has to be smaller than the rbw in order to make sure that there will be at least one bin that captures the full amplitude of the signal (is this correct?). But it’s still not so clear to me what will be the exact relation between rbw and bin size in the case where a flat-top window is used. Could you please explain this part in more detail?

The motivation behind this question is that I would ideally like to provide the SA124B with a frequency array that I generate myself (thus a particular bin size of my preference). Since I don’t see any way to change the bin_size directly from the provided API, I hope to be able to influence this bin_size setting through the rbw setting.

Speaking of rbw limitation, the limits I found in the SA44B-User-Manual.pdf (your link) is different from the one in https://signalhound.com/sigdownloads/SA44B/SA-API-Manual.pdf
In Page 39 Appendix: RBW and VBW, the first point of the list basically says that only 0.1Hz <= rbw <= 100KHz AND rbw=250KHz are allowed.
This is not consistent with one listed on the SA44B user manual where rbw from 0.1Hz TO 250 KHz as long as the frequency span and start frequency requirement is satisfied.

Thanks!