HF2LI-PID Quad PID Controller
The HF2LI-PID option builds on the HF2LI and seamlessly integrates no less than 4 high performance PID (proportional integral derivative) controllers for general purpose control. The controllers provide the means to efficiently implement closed loop control on several measured physical units.
HF2LI-PID Key Features
- 4 fully programmable PID controllers
- Full proportional, integral, derivative parameter control
- Flexible set point configuration: toggle, external, manual, cascaded
- Anti-windup
- Arithmetic engine
- PID Tuner and PID Advisor tool with 4 simulation models
HF2LI-PID Compatibility with Other Options
- Compatible with HF2LI-MF Multi-frequency option
- Compatible with HF2LI-PLL Dual Phase-locked Loop option
- Cannot operate in parallel with HF2LI-RT Real-time option
HF2LI-PID User Benefits
- Improve closed-loop bandwidth compared to LabVIEW implementation by orders of magnitude
- No external PID hardware required, better performance, less system noise
- Out-of-the-box closed-loop control solution: no programming required (e.g. LabVIEW,C)
HF2LI-PID Applications
- Automatic gain control (AGC)
- Kelvin probe force microscopy (KPFM)
- Dual-frequency resonance tracking (DFRT)
- SPM tip protection
- Axis control, Z-control for scanning applications
- Laser stabilization, Pound-Drever-Hall loops (narrow-band)
- Dual-sideband analysis (SNR improvement)
- Engineering of electronics
HF2LI-PID Functional Diagram
The HF2LI-PID ideally complements the HF2LI-PLL option for many resonance applications, but is also very attractive if just paired with the HF2LI lock-in amplifier. Zurich Instruments is the only lock-in amplifier vendor offering performant PID controllers in the same box, providing an evident integration advantage. The HF2LI-PID option is standard for the HF2PLL.
There is a variety of input units that can be selected, including demodulator outputs and auxiliary inputs. Also the output units selection is very flexible, offering control of units such as amplitudes, frequencies and auxiliary inputs.
An arithmetic engine allows specific calculations such as addition and subtraction of 2 demodulator outputs. Consequently several advanced applications are elegantly supported.
The PID Advisor tool is embedded in the graphical user interface and supports the user in efficiently determining loop parameters. This is often a time consuming task, but is very simple with the Zurich Instruments software. Moreover the loop can be simulated with 4 built-in models, increasing the likelihood of immediately finding appropriate settings. The PID Tuner can further support the optimization of the previously estimated parameters.
HF2LI-PID Specifications
| Configuration | Quad-PID |
| Regulation bandwidth | More than 5 kHz for each PID controller |
| Total update rate | 100 kSamples/s |
| Regulated units (PID inputs) | X, Y, R, and Theta from demodulators 1 to 6, auxiliary input 1 and 2, frequency deviation from PLL 1 & 2 |
| Controlled units (PID outputs) | Amplitudes of oscillators 1 to 8, frequency of oscillators 1 to 6, auxiliary outputs 1 to 4, digital output DIO (16 bit) |
| Controllable loop parameters | set point, center point, TC mode (time constant, gain) and PID mode (Kp, Ki, Kd), range, enable |
| Note: availability of the regulated/controlled units depends on installed options | |