Large PLC – Pages

Large Brick Open Source PLC

Created on: 23 April 2013

The OSPLC LARGE BRICK is an open-source PLC (programmable logic controller) that can be programmed using open source C language programming tools.

The Open Source PLC was designed to provide a C programmable PLC for embedded software engineers and programmers.

To find out more about applications for the OSPLC and the history of the OSPLC, see the page for the small brick open source PLC. The large OSPLC was designed to have more inputs, outputs and communication channels than the small OSPLC. It was designed in 2008 and released as open source hardware in April 2013.

Large Brick Open Source PLC (OSPLC)
Large Open Source PLC

This video shows the large open source PLC operating Festo Pneumatic valves and actuators in an automation demonstration.

Large Open Source PLC Features

Power Supply 12 to 24 Volts DC
Digital Inputs 22 Inputs with LED indicators (12 to 24V)
Digital Outputs 16 NPN open-collector (current sinking) outputs rated at 200mA each
Analogue Inputs 6 analogue inputs rated at 0V to 10V, 10-bit resolution
Communications 1 × USB device port, 2 × RS-232 ports (TX and RX only), 1 × RS-485 port, 1 × JTAG debug port
Real Time Clock Seconds, minutes, hours, day, month, years, and century
Automatic leap year compensation
Battery backup
Memory 256k bytes Flash memory for program and data storage
32k bytes SRAM for program and data storage
16k EEPROM for non-volatile storage, general-purpose use
SD card socket for SD or MMC memory card
Microcontroller AT91SAM7A3 32-bit ARM microcontroller from Atmel
Clock speed 48MHz
Mounting Uses standard DIN rail for mounting
Programming Code is loaded via the JTAG port

The image below shows the bottom side of the OSPLC large brick. The communication ports, analogue inputs and digital (transistor) outputs can be seen.

Side view of the large open source PLC showing communication ports
Side View of the Large Open Source PLC – 2 × RS232 Ports, USB Port, Analog Inputs and RS-485 Port Below (Black Connector)

This video shows a barcode scanner connected to the PLC. It is easy to get the barcode and display it on the RS485 LCD display by writing software in C.