create_voltage_probe_on_pin_group usage

[kestne]

Hi,

pyedb version = 0.34

I am trying to get DC resistance value between 2 pins in a given net. Pin A and Pin B.

Here is my script in brief.

1. Create 2 separate pin_groups for the 2 pins. (edb.siwave.create_pin_group)
2. Create current source between the 2 pin_groups. (edb.siwave.create_current_source_on_pin_group)
3. Create voltage probe between the 2 pins. (edb.siwave.create_voltage_probe_on_pin_group)
4. Setup DC analysis(edb.siwave.add_siwave_dc_analysis)
5. Siwave_solver
6. Finally, Output handler.

Now, all the steps works ok, except for step 3.
I see the below error,

 edb.siwave.create_voltage_probe_on_pin_group('v_probe', 'pin_grp1', 'pin_grp2')

ValueError                                Traceback (most recent call last)
Cell In[38], line 1
----> 1 edb.siwave.create_voltage_probe_on_pin_group('v_probe','pin_grp1','pin_grp2')

File ~\anaconda3\Lib\site-packages\pyedb\dotnet\edb_core\siwave.py:1360, in EdbSiwave.create_voltage_probe_on_pin_group(self, probe_name, pos_pin_group_name, neg_pin_group_name, impedance)
   1341 """Create voltage probe between two pin groups.
   1342
   1343 Parameters
   (...)
   1357
   1358 """
   1359 pos_pin_group = self.pin_groups[pos_pin_group_name]
-> 1360 pos_terminal = pos_pin_group.create_voltage_probe_terminal(impedance)
   1361 if probe_name:
   1362     pos_terminal.SetName(probe_name)

File ~\anaconda3\Lib\site-packages\pyedb\dotnet\edb_core\edb_data\sources.py:386, in PinGroup.create_voltage_probe_terminal(self, impedance)
    385 def create_voltage_probe_terminal(self, impedance=1000000):
--> 386     terminal = self.create_terminal()._edb_object
    387     terminal.SetBoundaryType(self._pedb.edb_api.cell.terminal.BoundaryType.kVoltageProbe)
    388     terminal.SetImpedance(self._pedb.edb_value(impedance))

File ~\anaconda3\Lib\site-packages\pyedb\dotnet\edb_core\edb_data\sources.py:363, in PinGroup.create_terminal(self, name)
    358 from pyedb.dotnet.edb_core.cell.terminal.pingroup_terminal import (
    359     PinGroupTerminal,
    360 )
    362 term = PinGroupTerminal(self._pedb, self._edb_object)
--> 363 term = term.create(name, self.net_name, self.name)
    364 return term

File ~\anaconda3\Lib\site-packages\pyedb\dotnet\edb_core\cell\terminal\pingroup_terminal.py:63, in PinGroupTerminal.create(self, name, net_name, pin_group_name, is_ref)
     61     if name in self._pedb.terminals:
     62         msg += f"Terminal {name} already exists."
---> 63     raise ValueError(msg)
     64 else:
     65     return term

ValueError: Failed to create terminal.

Questions,

1. Any solution for this error please?
2. Is there a better methodology to extract single-ended DC resistance between 2 pins? (No GND resistance required)
3. SiWave instance is invoked and shut down every time I run the script for different set of pins. Is there a way I can have the SiWave open and fast calculate DCR between different set of pins? (Any skeleton code would help)

Thanks

[svandenb-dev]

Hi @kestne,
1-thank you for sharing your issue. The error you get seems to comes from the fact you got a terminal already defined with the same name. The internal EDB api thrown an error when this happen. Could you please make sure you use unique names ?
2- I am not quite sure what you are asking, if you don't want reference (e.g. no current return path) you might consider using Q3D which is a quasi static solver. Btw the new release 2025R1 is providing a new beta feature using Q3D from layout (e.g with EDB).
3- I don't know exactly how your workflow is implemented but a new EDB should be created and solved for each project-setup variation. You can also call siwave_ng.exe and valcheck.exe along with .exec files to run all in batch without ui.
I hope it helps.