1. Úvod
This manual provides detailed instructions for the FNIRSI SG-004A Multi-functional Signal Generator. Please read it carefully to ensure optimal use and understanding of the product's features and functions. The SG-004A is designed for a wide range of applications, including PLC system debugging, DCS system debugging simulation, valve positioner adjustment, instrumentation calibration, and inverter detection.
Video: Unboxing and demonstration of the FNIRSI SG-004A signal generator's features and dimensions.
2. Bezpečnostní pokyny
- Read this manual carefully to ensure proper operation and to obtain the best performance from the product.
- Nepoužívejte přístroj v hořlavém nebo výbušném prostředí.
- Used batteries and discarded instruments must be disposed of in accordance with relevant national or local laws and regulations, not with household waste.
- If you encounter any quality problems or have questions about using the instrument, contact FNIRSI customer service or the manufacturer for assistance.
- WARNING: The safety limit voltage of the input terminal cannot exceed 30Vpp. Exceeding this limit will damage the equipment.
3. Konec produktuview
3.1. Key Features and Applications
The FNIRSI SG-004A is a multi-functional signal generator capable of handling various signal types for debugging, simulation, and calibration tasks.

Image: The SG-004A supports DC Voltage, Current, Analog Source, Thermocouple Signal, RTD Signal, 24V Power Distribution Output, and Program Output.

Image: Applications include PLC System Debugging, DCS System Debugging Simulation, Valve Positioner Adjustment, Instrumentation Calibration, and Inverter Detection.
3.2. Interface Terminals
The device features 4 inner diameter 4mm wiring ports on the top surface, color-coded for easy identification:
- červená (OUT): Output port, forms a pair with the black (COM) port.
- Black (COM): Common ground for input and output.
- Yellow (IN+): Positive input port.
- Blue (IN-): Negative input port, can also function as an independent 24V test power supply. When used as an independent 24V supply, there is a 24V voltage between the (COM) port and the (IN-) port.

Obrázek: Podrobný view of the SG-004A's buttons and interface ports, including Input, Output, Function, Auto, On/Off, Curve, Preset, Convert, and the 2.4-inch TFT Full Color LCD Screen.
3.3. Power & Charging
- Baterie: Built-in 3000mAh large capacity lithium battery.
- Displej baterie: Current battery percentage is shown in the upper right corner of the display.
- Nabíjecí rozhraní: Type-C port (DC 5V-12V).
- Stav nabíjení: When charging (up to 10W), the power button displays a red light. Once fully charged, it automatically stops charging and displays a blue light.
5. Display & Signal Description
5.1. Switching Signal Types
- From the main interface, press the FN button until it turns red. Then, press the IN button to enter input settings or the VEN key to enter output settings. Navigate left/right to select the desired signal type. Press FN znovu k výstupu.
- Various signal modes are available, each with different configurable parameters.
5.2. mA Current Signal
- Přepínač režimů: In the main interface (FN white), press IN/OUT to switch between actual value and engineering quantity display.
- Output Open Circuit Detection: If the output is on and the interface flashes "open circuit", it means the output signal is not connected or is near zero.
- Output Circuit Voltage: The SG-004A can set current output no-load voltage. 12V is used to save power, while some devices require 24V drive capability.
- Výstupní rozsah: The limit range for current output can be set.
5.3. V Voltage Signál
- Přepínač režimů: In the main interface (FN white), press IN/OUT to switch between actual value and engineering quantity display.
- Nadproudová ochrana: If the output voltage is shorted, the output will automatically shut down.
- Výstupní rozsah: The limit range for voltage output can be set.
5.4. XMT Passive Current Signal
- Přepínač režimů: In the main interface (FN white), press IN/OUT to switch between actual value and engineering quantity display.
- Výstupní rozsah: The limit range for passive current output can be set.
5.5. Hz Pulse Signal
- Režimy: Frequency, PWM duty cycle, speed frequency, pulse quantitative/counting.
- Přepínač vstupního režimu: In the main interface (FN white), press IN to switch modes directly.
- Přepínač výstupního režimu: Dlouhé stisknutí VEN pro přepínání režimů.
- Frekvenční rozsah: Select from 0~99.999Hz, 0~999.99Hz, 0~9999Hz, 0~200kHz.
- Metoda: Select level/open circuit based on pull-up presence.
- Output Peak Value: Max 24V.
- Input Counting Method: Rising edge (OV to peak) or falling edge (peak to OV) increments counter by 1. "Jump" increments on any level change. Long press IN to clear count.
- Frequency Mode Operation: Input frequency range 0~9999Hz (auto decimal shift). Output frequency range switched by pressing VEN (FN white).
- PWM Mode Operation: Displays frequency (period) and duty cycle. Max frequency 9999Hz. Parameters can be set during output. Yellow cursor indicates selection when FN is white and VEN je stisknuto.
- Speed Mode Operation:
- Calculates motor/gear speed (1 revolution = 1 pulse).
- Time Unit: RPS (per second), RPM (per minute), RPH (per hour). Max frequency 9999Hz.
- Number Of Revolution Pulses: Selectable in speed setting.
- Tooth Missing: Simulates engine speed.
- Quantitative/Counting Mode Operation: Simulates flow control sensors (quantitative) or flow counts (counting). Input frequency value displayed. For output, cycle displayed in milliseconds. When FN is white, press VEN to switch between cycle and quantitative values. Cursor disappears after output, backlight turns blue, buttons change function (up: single pulse, down: program stop/reset, left: no function, right: start/pause).
5.6. mV Millivolt Signal
- Režimy: 110mV, Thermocouple, WR Thermocouple. Switch by pressing IN/OUT when FN is white.
- Typy termočlánků: TC-S, B, E, K, R, J, T, N.
- WR Thermocouple Types: WRE25, WRE26.
- Jednotka teploty: Celsius or Fahrenheit.
- Cold Junction Setting: Meter-detected or user-defined temperature.
- Cold End Temperature: Customized value.
5.7. 24V Loop Detection
Select the "24V" label in the OUT signal type interface to enter this function. The main interface will display the output 24V loop current. This supports unlimited input signal detection types.
- Smyčka 1: Outputs 24V between (OUT) and (COM) ports, detects loop current, and displays it in the "output 24V loop" area. Useful for testing pneumatic control valves or two-wire transmitters.
- Smyčka 2: Activates independent 24V power supply. The (IN-) port outputs 24V between (24V) and (COM) ports, without affecting input signal detection. Select mA for input. (IN-) and (IN+) can form a 24V output while detecting current loop.
- Independent 24V Supply: (IN-) port can be switched to independent 24V power supply, outputting a single DC24V voltage (the 24V port). Used with (IN+) to test two-wire transmitters.
Poznámka:
- 24V loop detection measures feedback current from the output signal port.
- Independent 24V port and output port can form a 24V power supply, or combine with input (+) for a transmitter to supply power and measure feedback current.
5.8. Ohm Resistance Signal
- Jednotka teploty: Celsius or Fahrenheit.
- Typy odporu: Pt100, Cu50, and RES. Switch by pressing IN/OUT when FN is white.
- Resistance Offset: Corrects input/output resistance values.
6. Extensions
6.1. Engineering Quantity Conversion
For analog signals in industrial applications, it's often necessary to convert them to engineering quantity values. The instrument allows setting upper and lower limits for both engineering quantity and corresponding signal values in the input and output settings.
6.2. Preset Value
- Nastavení parametrů: Configure signal values for the up, down, left, and right buttons.
- Operace: When FN is red, press the PRESET key to start/exit preset mode. Once active, the up/down/left/right keys' backlights turn green, and their functions change to output the set values.
6.3. Signal Conversion
Converts an input signal into an output signal. For example, an input frequency signal (0-1000Hz) can be converted into a current signal (4-20mA).
- Nastavení parametrů:
- Input upper/lower limit: Amplitude range of input signal.
- Output upper/lower limit: Amplitude range of output signal.
- Overrun allowed: If checked, 1-5V converts to 4-20mA. If input is 0V, output follows to 0mA. If unchecked, output is 4mA and locked within range.
- Automatic operation: If checked, signal conversion starts automatically on next power-on and stops when exited.
- Instrukce: When FN is red, press KONVERTOVAT to start/exit signal conversion. Backlights of up/down/left/right keys turn off.
6.4. Program Output
Automatically performs N cycles of signal output based on set parameters, useful for aging tests of electric/pneumatic valves or PLC program debugging.
- Nastavení parametrů:
- Mode: Single rise, single fall, or cycle.
- Number of loops: 0 for infinite, max 30000.
- Start value, End value, Increment step value, Increment step time, End stop (delay), Decrement step value, Decrease step time, Loop stop (delay).
- Instrukce: When FN is red, press AUTO to start/exit programming output. Backlights of up/down/left/right keys turn blue. Functions change to single run (up), program reset (down), single-step run (left), Stop/Continue (right).
6.5. Křivka v reálném čase
Displays input and output signal trends graphically. Sampling time is adjustable, and the curve automatically scales within max/min values.

Image: Real-time curve display on the SG-004A, showing input and output signal trends. Up to 100,000 or 15 sets of data can be recorded.

Obrázek: Podrobný view of the real-time curve record, including history view and curve display.
- Instrukce: When FN is red, press KŘIVKA to switch the interface with/without curve.
- Parametry: Output curve (red line), automatic output scaling, input automatic scaling, acquisition time (refresh interval).
6.6. History Record
- Enable/Close Recording: When FN is red, press ON/OFF. The record number flashes on the screen.
- View Záznam: Select a record in the setting interface history record, then ON/OFF to enter. Backlights of up/down/left/right keys turn yellow. Up/down views 100 record values, left/right views 1 record value.
- Smazat záznam: Zatímco viewing a record, press ON/OFF.
6.7. Output Time
- Output Activation Output Time: When checked, output automatically turns off after the set time expires.
- Čas výstupu: Set the desired output duration.
6.8. Sdělení
- Připojení USB: Uses USB analog serial port for communication. Note that charging will be slower when USB connection is active.
- Modbus Slave: The SG-004A can communicate with configuration software or PLC via RS485. Refer to the attached tables (not included in this manual, but available in the full PDF) for register addresses and descriptions.
7. Pokyny pro zapojení
Správné zapojení je zásadní pro přesné měření a bezpečný provoz. Běžné scénáře zapojení znázorňují níže uvedené diagramy.

Image: Wiring diagrams illustrating connections for PLC/Process instruments (all-round signal output) and pneumatic valves (valve position given/feedback). The diagrams show how to connect the SG-004A's IN, OUT, COM, and 24V ports for various signal types.
7.1. Connecting to PLC/Process Instrument
For all-round signal output (Current/Voltage/Millivolt/Frequency/Resistance/Thermal Resistance/Various Thermocouple Signals), connect the SG-004A as shown in the top two diagrams of the image. The connections are switched by electronic switches.
7.2. Connecting to Pneumatic Valves
For valve position control and feedback, refer to the bottom two diagrams in the image:
- Valve Position Given/Feedback (Power Supply from SG-004A): Switch the IN(-) port to 24V to act as the power supply for valve feedback. Input and output are performed simultaneously.
- Valve Position Given/Feedback (IN(-) as Negative Pole): The IN(-) port is closed to 24V and acts as the negative pole of the input signal. Input and output are performed simultaneously.
8. Řešení problémů
8.1. Fault Resolution
- No response when SG-004A is turned on:
- Check if the battery has power and if the charging indicator light is normal when charging.
- A firmware upgrade error operation might lead to a system crash.
- Abnormální zobrazení na obrazovce: Check if the screen is connected properly.
- Abnormal output value or measured value:
- Check the signal line connections.
- Verify the interface for signal selection.
- Ensure the target parameter of the connection does not exceed the technical indicator range, as this can cause abnormal operation or damage.
- Error in input and output: Some errors are normal as input and output are not isolated.
8.2. Údržba zařízení
- The meter is powered by a 3.7V rechargeable lithium battery. Use the power adapter to extend battery life during long periods of use.
- This instrument is not waterproof; avoid using it in high humidity environments.
- Do not place the unit in unstable locations, or where it may be subject to strong vibrations.
- Avoid high humidity, dust, direct sunlight, outdoor exposure, or high temperatures.
8.3. Aktualizace firmwaru
The SG-004A supports firmware upgrades via a USB emulated U disk.
- Plug the meter into a PC and turn it on. Wait for the PC to recognize the USB drive named "Bootloader".
- Zkopírujte nový firmware file to the "Bootloader" U disk.
- After a few seconds, the device will power on normally, and the upgrade will be successful.
Important Notes for Firmware Upgrade:
- If the U disk is not recognized normally when connected to the PC, shut down and restart the device.
- USB firmware upgrade only supports Windows 10. Do not drag or drop files other than those officially released by FNIRSI, as this may cause irreversible damage.
9. Specifikace
The following tables detail the technical parameters and capabilities of the FNIRSI SG-004A Multi-functional Signal Generator.

Image: Comprehensive table of technical parameters including signal scope, precision, resolution, internal impedance, output signals, input signals, and extended functions.
9.1. Obecné specifikace
| Vlastnictví | Hodnota |
|---|---|
| Číslo modelu | SG-004a |
| Název značky | FNIRSI |
| Potřeby pro kutily | Elektrický |
| Původ | pevninská Čína |
| Osvědčení | CE |
| Velikost displeje | 2.4 palce a méně |
| Baterie je součástí dodávky | Ano |
| Rozhraní | Typ-C |
| Vstup | 5-12V/10W(Max) |
| Kapacita baterie | 3000 XNUMX mAh |
| Pohotovostní doba | 24h |
| Rozměry (D*Š*V) | 112mm * 77mm * 21mm (approx.) |
| Čistá hmotnost | 66 g (cca) |

Image: Basic properties, power properties, and packing list for the SG-004A, including dimensions.

Image: Detailed dimensions of the SG-004A: 82mm (3.23in) width, 28mm (1.10in) thickness, 112mm (4.41in) height, and 166g (0.37 pounds) weight.
9.2. Signal Output/Input Ranges & Precision
| Typ signálu | Rozsah | Přesnost | Rezoluce | Impedance |
|---|---|---|---|---|
| Proud (mA) | 0-24 mA | ± (0.02% + 0.003) | 0.001 mA | 100Ω |
| svtage (V) | 0-24V | ± (0.02 % + 0.003) | 0.001V | 500 tis |
| pasivní (XMT) | 0-24 mA | ± (0.02% + 0.003) | 0.001 mA | 100Ω |
| 24V smyčka | 0-24 mA | ± (0.1% + 0.005) | 0.01 mA | 100Ω |
| Frekvence (Hz) | 0-9999Hz | ±2 % | 5 číslic | 1 MK |
| Milivolt (mV) | -10~100mV | ± (0.03 % + 0.03) | 0.01mV | 2K |
| TC (TC-S) | 0-1760 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (TC-B) | 0-1810 °C | ± (0.5 % + 1) | 1 °C | 2K |
| TC (TC-E) | 0-990 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (TC-K) | 0-1320 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (TC-R) | 0-1760 °C | ± (0.3 % + 1) | 1 °C | 2K |
| TC (TC-J) | 0-1190 °C | ± (0.3 % + 1) | 1 °C | 2K |
| TC (TC-T) | 0-390 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (TC-N) | 0-1290 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (WRe3/25) | 0-2320 °C | ± (0.2 % + 1) | 1 °C | 2K |
| TC (WRe5/26) | 0-2320 °C | ± (0.2 % + 1) | 1 °C | 2K |
| RES (ohm) | 0-390Ω | ± (0.2 % + 1) | 0.1Ω | / |
| 100 Pt | -200~650°C | ± (0.5 % + 1) | 0.1 °C | / |
| Cu50 | -20~150°C | ± (0.5 % + 1) | 0.1 °C | / |

Image: High precision testing results for mA input/output and Voltage input/output, demonstrating accuracy.

Image: High precision testing results for Resistive Output, Millivolt Output, Rotating-speed Test, and Programming Test.
10. Uživatelské tipy
- Versatile Calibration: The SG-004A is highly versatile and can be used to calibrate various sensors and transmitters, including Pt100 RTDs and thermocouples. Ensure you select the correct signal type and parameters for accurate calibration.
- Understanding Signal Types: Take time to familiarize yourself with the different signal types (mA, V, Hz, mV, Ohm, TC, RTD) and their specific settings to fully leverage the device's capabilities for your application.
- Aktualizace firmwaruPravidelně kontrolujte pokyny výrobce website for new firmware versions to ensure your device has the latest features and bug fixes. Always follow the upgrade instructions carefully.
11. Záruka a podpora
FNIRSI products undergo strict quality inspection. If you have any questions or need help, please contact FNIRSI customer service or the manufacturer directly.
A digital version of this user manual (PDF) is available for download. You can find it and any available firmware updates by scanning the QR code on the last page of the original manual or visiting the manufacturer's website. The PDF manual can be accessed at: FNIRSI SG-004A User Manual (PDF)
Výrobce: Shenzhen FNIRSI Technology Co., Ltd.
Webmísto: www.fnirsi.cn
Adresa: budova C, průmyslový park Weihuada, ulice Dalang, okres Longhua, Shenzhen, Guangdong, Čína
12. Výrobní informace
Product Name: Multi-functional Signal Generator
Značka / Model: FNIRSI / SG-004A
Výrobce: Shenzhen FNIRSI Technology Co., Ltd.
Webmísto: www.fnirsi.cn
Adresa: budova C, průmyslový park Weihuada, ulice Dalang, okres Longhua, Shenzhen, Guangdong, Čína






