OEM PLC

Fulmatic PLC development board OEM PLC. Build your own PLC using the Fulmatic CORE PLC firmware library. You can utilize the OEM PLC as a PLC development board during your firmware development process or as a compact PLC for your industrial automation projects.

This circuit board has been specifically designed to serve as the reference schematic for the Fulmatic Core library. With a total of 42 I/O points and 115 KB of PLC memory, it offers a remarkably high capacity for its class.

  • Can be operated at 12V or 24V.
  • The memory capacity is 115 KB, all of which can be utilized for PLC code or as retentive memory (Data blocks).
  • 16x DI: Digital Inputs (up to 200 kHz)
  • 16x DQ: Digital Outputs (655 kHz, 100 mA)
  • 8x AI: Analog Inputs (0-10V / 0-20 mA)
  • 2x AQ: Analog Outputs (0-10V)
  • 2x RS485 ports
  • 1x Ethernet port.
  • RTC (Real-Time Clock): Maintains time for up to 30 days via supercapacitor.

Our circuit is powered by the STM32F407VGT6 microcontroller. The circuit schematics are provided as open-source. You are free to manufacture and commercialize your own version of this hardware. By utilizing the Fulmatic Core library, you can modify the C code to suit your specific needs.

Representative Image
Circuit Schematic
Gerber Files

General Specifications

  • The PLC is non-isolated. The supply voltage can be sourced from different inputs; however, all GND points are interconnected on the circuit board. You must also interconnect all GNDs using terminal blocks within your panel.
  • All inputs and outputs are protected. Your board will not be damaged by incorrect connections or interference. This protection is limited to 24 volts.
  • All inputs and outputs are 12 / 24 volt compatible. The D9 Zener diode must be 16 volts for 24V operation and 5.1 volts for 12V operation. 24V PLC order code: SC-02418-00-00, 12V PLC order code: SC-02418-00-12.
  • There are 2x RS485 ports. It can also be configured as 1x RS485 and 1x RS232, or 2x RS232.
  • 8 analog inputs are configured for 0-10 volts. When you bridge the JP0-JP8 jumpers with solder, you can use them as 0-20 mA.
  • 2 analog outputs are configured for 0-10 volts. To use 0-20 mA, you must add an external resistor. You can calculate the required resistor value using the formula: $Resistor Value = 500\,\Omega – Internal\,resistance\,of\,the\,reading\,device$.
  • J7, J8, and J9 sockets are not installed on the board. You should provide and install them if needed.
  • Since it is an open board, do not touch it with bare hands; you must strictly follow static energy safety precautions.
  • The OEM PLC does not carry any warranty. The product is shipped 100% tested and functional. No warranty is provided as it is not enclosed in a protective housing.

Shutdown Circuit

The Fulmatic PLC must detect a power failure, execute the OB 1 Shutdown block, and save the PLC code to flash memory. The image illustrates the +24V supply voltage and the +23 circuit, which provides power for an additional 1-2 seconds after a power outage. The D2 diode prevents internal energy from being consumed by external devices. The R3 resistor prevents the large capacitor from creating a current surge during charging. The D78 diode ensures that the energy stored in C1 is transferred to the circuit without loss when power is disconnected.

The PB2 pin goes low when the voltage drops to approximately 19-20V. The PLC Firmware detects this state and initiates the shutdown procedures. For 24V operation, the D9 Zener diode must be 16V, while for 12V operation, it should be 5.1V. A C1 capacity of 1000 µF is at the threshold; since capacitance decreases as it ages, it should be at least 2200 µF. Additionally, you must consider the other power requirements of your circuit. In your C code, you should turn off high-current-consuming circuits when a shutdown is detected, or you may need to use a larger capacity.

License

There is no license requirement when you purchase the OEM PLC from us. However, you must purchase a license if you wish to modify the C code using the Fulmatic Core library. The U4: ATSHA204A-SSHDA chip used for licensing is not installed on the board. You must source and install the chip yourself. You may request one from us as a sample.

Downloads

  • You can download the circuit schematic as a PDF here.
  • You can download the Proteus project and Gerber files here.