How to Verify Initial Software Issue Without RF Hardware Device

When you want to verify some software basic function ， but there is not any RF device (cards) on hand. Is there some solution to verify the software without hardware basically in time ? 
When your customer find one initial software issue when measuring ,  you want to reproduce the issue but you have no RF devices. How did you continue reproduce the issues for debugging ? 

For example as below :
One customer measure their DUT with our RFIC Test Software by PXIe-5831 , they found that when setting DUT Input Frequency(8GHz) different from DUT Output Frequency(25GHz) with IF to RF Enabled, 
 the RFIC 19.0.1 appeared  one error that means RFSG/SA all used the same frequency limit .( User expects SG = DUT Input Frequency, SA = DUT Output Frequency. )

Details Steps:

1)    Using PXIe-5831 and RFIC Soft Front Panel 19.0, setting SG Port = if0, SA Port = rf0/port0

2)    Set IF to RF Enabled = True

3)    Set DUT Input Frequency = 8GHz and DUT Output Frequency = 25GHz. Without run, no error is reported.

4)    Once run the acquisition, an error is thrown saying that incorrect requested frequency set in the RFmx. It reports that 8GHz is set at RFmx, which is not in the mmWave range of 5831.

Customer had no time to support us debugging the issue with their equipment , we should used our station to reproduce and debug it in time.   

If you don't have the device PXIe-5831 , do you have one solution to verify the issue ?

The answer is "yes" , we could simulate one PXIe-5831 and try to verify the issue in time.
Before you create the simulated device , we could check the NI MAX status first as below:

Follow below steps , you could add some simulated devices in NI MAX later. 
1>You should installed Test Stand and TSM module. 

2. Create one Offline Mode configuration file about how to create one PXIe-5831 , detail refer to below:

3. Enable the Semiconductor Mode in Teststand

4. Enable TSM Offline Mode

5. When you enabled the offline mode , one window appeared for you to chose the cfg files

6. After selected the cfg files , you need waiting for a moment for updating the simulate device

7.After updated ok , you will find the simulated devices in NI MAX 

We could see the simulated devices in NI MAX , then we could try to verify the RFIC software issue with the simulated devices.

1.Try to select the simulated device when setting the configuration in RFIC Test software

2. We could normal run the RFIC Test software with the simulated device. （even the measurement result is no changing and un-useful)

This is one solution to verify the initial software issue without the really hardware devices for your reference.