Best 4-20 mA Signal Generators for PLC Testing and Calibration
Answering exactly what you’re seeking, this guide highlights top 4-20 mA signal generators ideal for PLC testing, calibration, and electronic maintenance. These devices cover current and voltage output, offer multiple signal types, and provide battery or USB power options for mobile or bench work. They’re best for technicians, maintenance engineers, and anyone needing precise, on-site signal simulation without elaborate setup.
Top picks span compact pocket models for on-site work to USB-rechargeable units for longer tasks. The following table compares five strong options to help you decide quickly based on output range, power source, and display features.
| Product | Output Range | Power | Display | Best For |
|---|---|---|---|---|
| Riiai SG003A | 4-20 mA / 0-24 V | Built-in 3000 mAh USB | 2.4 inch TFT | PLC testing on the go |
| Riiai SG004A | 4-20 mA / 0-24 V | 1500 mAh rechargeable | Compact display with PWM | Portable, programmable tests |
| DROK 4-20mA Generator | 0-10 V / 4-20 mA | USB-powered | LED display | Clear, dual signal generation |
| UCTRONICS DC ±10V / 0-20mA | ±10 V / 0-22 mA | USB or DC 15-30V | None specified | Analog simulation with flexible supply |
| DROK 4-20mA Generator 2pcs | 0-10 V / 0-20 mA | USB powered | 3-digit LED display | Two-channel redundancy |
Riiai DC 0-10V / 0-4-20mA Signal Generator
Best for technicians who need both voltage and current output with an adjustable encoder. Output voltage ranges from -10V to +10V with 0.01V precision, and current output spans 0-22 mA with 0.01 mA precision. The device features a built-in 1000 mAh battery and multiple power options (micro USB 5V or external DC 15-30V) to support field work. Caution: accuracy depends on calibration and battery charge level.
Riiai SG003A 4-20mA / 0-24V Signal Generator
Designed for PLC testing with a 4-20 mA current signal and a 0-24 V voltage signal. It includes a 3000 mAh USB rechargeable battery and a 2.4 inch TFT color display for easy night or day use. Best for engineers who need long operation time between charges and a clear display. Limitation: battery life depends on output load and display brightness settings.
Riiai SG004A 4-20mA / 0-24V Programmable Generator
Offers integrated current/voltage output plus PWM, with a portable 1500 mAh battery for cord-free operation. It provides high-precision output (0-24 mA with 0.05 mA accuracy, and ±12 V with 0.03 V accuracy). Best for on-site electronic maintenance where wireless use matters. Caution: ensure you have a compatible USB charger during extended work sessions.
UCTRONICS DC ±10V / 0-22 mA Signal Generator
A versatile option with external power or USB input, providing DC ±10 V output with 0.01 V precision and 0-22 mA current output with 0.01 mA precision. Best for bench setups where a stable external power supply is readily available. Limitation: battery option is not included, so mobility is reduced without external power.
DROK 4-20mA Generator (Two Units)
Offers dual signal generation: 0/4-20 mA current signal and 0-10 V voltage signal controlled by a precise potentiometer. Features a bright 3-digit LED display for easy monitoring and back calibration screws to adjust output. Best for users who want a compact two-channel approach and straightforward calibration. Caution: the need to verify display calibration after device transport or battery changes.
LB78 Current Voltage Signal Generator
A robust calibrator with calibrated DA and reference components designed for PLC maintenance, DCS, and field instruments. It emphasizes fast, independent keys and built-in protection against misconnection. Best for technicians requiring dependable protection and clear tactile control. Limitation: description notes energy protection but does not specify battery or portable use, so it’s more suited to lab benches or vehicle-enabled service carts.
Buying Guide: Key Purchase Considerations
- Measurement range and precision: Choose devices that match your target signal types (current 4-20 mA and voltage 0-24 V) and meet needed resolution (often 0.01 mA or 0.01 V).
- Power source and portability: Decide between USB, battery-powered, or external DC supply based on field use versus fixed bench work.
- Display type and readability: TFT color screens and LED readouts improve visibility in varied lighting; consider night or bright environments.
- Multiple signal types: Some units support PWM, HZ pulses, and multiple modes—useful for diverse PLC testing scenarios.
- Calibration and stability: Look for devices that allow easy calibration and have stable references for long-term testing.
- Physical design and durability: Portability, rugged casing, and plug-and-play ports reduce setup time in the field.
Practical Buyer Questions
- What output ranges should I prioritize for PLC testing? – Prioritize devices offering 4-20 mA and 0-10 V/0-24 V with fine 0.01-unit precision for accurate calibration.
- Is a battery-powered generator better for on-site work? – Yes, battery power supports cord-free operation, improving mobility for field maintenance.
- Do I need PWM or frequency output? – If your testing includes signal modulation or digital control, a model with PWM and Hz outputs speeds up tasks.
- Should I buy a two-channel DROK unit? – A two-channel unit is advantageous when you want simultaneous dual-signal testing or quick cross-verification.
- What is the importance of a clear display? – A readable display reduces setup mistakes and makes night work feasible without extra lighting.
- How important is calibration capability? – Calibration ability ensures the device remains accurate over time and after transport.
Note: This article presents five relevant options from Riiai, DROK, and UCTRONICS families based on their advertised outputs and features. Always verify compatibility with your specific PLC make and model before purchasing.