FNIRSI Function Generator Model SG-004A; Multifunction Calibrator 0–24mA/0–24V with Frequency Output up to 10kHz for PLC and DCS
For engineers who need a truly versatile tool
If you constantly switch between multiple devices for debugging PLCs, simulating DCS, adjusting valve positioners, or testing inverters, the SG-004A shines exactly where ordinary tools fall short. This multifunction signal generator/calibrator from FNIRSI provides 0–24mA current, 0–24V voltage, frequency up to 10kHz, and mV input/output (for thermocouple simulation) in a compact, battery-powered unit; along with real-time waveform display, input-to-output signal conversion, and history recording—everything needed for fieldwork and quick commissioning.
Why is the SG-004A the first choice for fieldwork and commissioning?
Multiple vital signals in one device: current source, voltage source, frequency/pulse, and mV for thermocouples—instead of carrying several separate calibrators.
Industrial-level sourcing and sinking: 0–24mA and 0–24V cover the 4–20mA and 0–10V standards in PLC/DCS and drive inputs/outputs.
Frequency up to 10kHz: suitable for testing high-speed pulse/counter inputs of PLCs and simulating common frequency signals.
Suitable accuracy and resolution for instrumentation: 0.001mA and 0.001V resolution; industrial-class accuracy (about 0.2% depending on mode).
Live display and data logging: view signal curve in real-time and review history for evidence-based troubleshooting.
3000mAh battery with Type-C charging: approximately 10 hours of operational use and long standby; perfectly suited for field projects.
2.4-inch color display: high readability in varying industrial lighting conditions.
Pocket-sized: 112×77×21 mm and only 167 grams—always handy without hassle.
Deeper engineering; what makes a practical difference
0–24mA current source with precise control: simulate 4–20mA for calibrating PLC analog inputs, testing valve positioners, and checking current loop behavior. 0.001mA resolution lets you make fine step adjustments and measure hysteresis.
0–24V voltage source with 1mV steps: calibrate 0–5V and 0–10V inputs/outputs on analog cards, drives (VFD/inverters), and controllers.
Frequency output up to 10kHz: stimulate high-speed digital inputs (HSC/Counter), simulate speed sensors, or test pulse counting paths in PLCs.
mV input/output for thermocouples: simulate and receive mV thermocouple signals for testing and matching temperature channels. Ideal for calibrating measurement chains without heat sources.
Input-to-output signal conversion: map one input simultaneously to a desired output signal (e.g., convert 4–20mA to 0–10V) and instantly see loop response—ideal for testing transmitters and I/O cards.
Auto Lift (Ramp) output program: generate controlled ramps (step or continuous) for process testing—check valve start points, dead zones, response speed, and stability.
Real-time curve and history: observe system behavior live and keep history for later analysis—data-driven troubleshooting instead of guesswork.
MODBUS communication support: integrate into industrial control environments and digital workflows.
Use cases that shorten project delivery time
PLC debugging and I/O commissioning: inject 4–20mA to AI input, 0–10V to AO, and pulses up to 10kHz to high-speed DI—match control software to field reality before process commissioning.
DCS simulation in commissioning: test instrumentation loops, signal mapping, and alarm/interlock checks with programmed ramps.
Valve positioner adjustment: 4–20mA current ramp to check hysteresis, repeatability, and zero/span points; observe response on the live curve.
Instrument testing and calibration: verify and adjust pressure/temperature/flow transmitters with stable reference signals—no bulky lab equipment needed.
Inverter (VFD) testing: verify 0–10V/4–20mA analog inputs and frequency inputs; simulate speed commands and observe drive behavior.
Key technical specifications
Feature
Value
Description
Current mode
0 to 24 mA
0.001 mA resolution; suitable for 4–20 mA simulation
Voltage mode
0 to 24 V
0.001 V resolution; covers 0–5V and 0–10V
Frequency/Pulse mode
Up to 9,999 Hz (~10 kHz)
Suitable for HSC/Counter in PLC
mV Input/Output (Thermocouple)
Yes
Simulate/measure mV for temperature channels
Measurement/Output Accuracy
About 0.2% (depends on mode)
Industrial class, suitable for field calibration
Display
2.4-inch color TFT
High readability with backlight
Data Logging
History + real-time graph
Monitor behavior and document tests
Features
I/O conversion, auto ramp
Signal mapping and dynamic loop testing
Battery
3000 mAh lithium
About 10 hours operation; Type-C charging
Dimensions/Weight
112×77×21 mm / 167 g
Easy to carry, field-friendly
What sets this model apart from ordinary tools?
Signal integration: current, voltage, frequency, and mV in one device—faster setup and reduced wiring errors.
Data-driven troubleshooting: real-time and historical curves beyond simple numeric display.
Field efficiency: high-capacity battery, Type-C charging, pocket size, and clear color display.
Ready for industrial control: input-to-output conversion, pre-programmed ramps, and MODBUS support for existing infrastructure integration.
Frequently Asked Questions
Can the SG-004A fully simulate 4–20mA loops?
Yes; it can output 0–24mA with 0.001mA resolution and is ideal for simulating 4–20mA on PLC/DCS analog inputs and current-driven actuators. For powering two-wire transmitters, ensure an appropriate loop power supply exists.
Is the frequency output suitable for high-speed PLC inputs?
Yes; up to about 10kHz output is suitable for testing counters/HSC, and pulse inputs can be simulated without real sensors.
Does it support history recording and review?
Yes; in addition to real-time curve display, it saves test history for later system behavior review.
What is the battery capacity and charging method?
3000mAh battery with USB Type-C charging; designed for long field use and lasts about 10 hours under normal conditions.
How does it assist with temperature calibration?
With mV input/output, you can simulate or test thermocouple-based channels; ideal for quick matching and calibration of temperature measurement paths.
In summary, if you want a compact, precise, field-oriented tool that covers current, voltage, frequency, and mV signals simultaneously and elevates troubleshooting with curves and history, the FNIRSI Function Generator Model SG-004A is a choice that quickly proves itself on every project.
Esfahan