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LCR Driver Range Not Working #243
Description
The range function in the LCR driver is not working. The issue is that we attempt to perform a fancy string to number to string coversion. The LCR will only take the following in its SCPI commands (tested manually)
📖 SCPI Command Reference
The driver wraps these low-level serial commands into high-level Python methods.
| Command | Parameter Options | Description | Example Usage | Example Return (Blank means no return value) |
|---|---|---|---|---|
*IDN? |
- | Identity check | *IDN? |
Agilent Technologies,U1732C,... |
SYST:ERR? |
- | Error queue check | SYST:ERR? |
+0, "No error" |
MODE |
SER, PAL |
Series vs Parallel | MODE SER |
- |
DISP2 |
D, Q, TH |
Set secondary parameter | DISP2 Q |
- |
FREQ |
100, 120, 1k, 10k |
Test frequency (Hz) | FREQ 1k |
- |
FUNC |
R, C, L, Z, ESR, AI |
Primary measurement type | FUNC C |
- |
RANG |
See Range Table below | Set manual range | RANG 20u |
- |
FETC? |
- | Read primary value | FETC? |
+6.856E-07 |
FETC? ALL |
- | Read all parameters | FETC? ALL |
Rs,+3.809052E-13,Ls,+4.316664E+09,Rp,+6.172276E-14,Lp,+4.316802E+09,Z,+4.316733E+09,TH,+5.774222E-01,F,+1.000000E+03,D,+1.774207E+02,Q,+5.636322E-03 |
📉 Range Options by Function
| Function | Available Range Arguments |
|---|---|
| R / Z | 2, 20, 200, 2k, 20k, 200k, 2M, 20M, 200M |
| L | 2000u, 20m, 200m, 2, 20, 200, 2k |
| C | 2000p, 20n, 200n, 2000n, 20u, 200u, 20m |
Activity
daniel-montanari commentedon May 29, 2026
In addition to this there are a few other drivers that use this
Keysight 33500b - turns fixed strings into numbers
rigol dg1022 - turns fixed strings into numbers
agilent u1732c (this driver) - turns arbitrary input into numbers (with bugs)
I think we should remove unit_scale entirely, fix up any scripts that rely on it, and delegate any sort of api related behaviour to drivers only, and force users to put numbers in, instead of strings with multiple formats.