UniPi Neuron M403 PLC features high number of relay outputs, offering 28× RO. The M403 is a smaller variant of the L403 model.
The product features an integrated Raspberry Pi 3 Model B computer
The M403's I/O architecture is focused on a large number of relay outputs while retaining the basic digital I/O capability. That makes the unit suitable for larger projects focusing on switching two-state devices by alternating or direct voltage (boilers, water heaters etc.). The unit also serves as a smaller variant of the L403 unit.
Digital inputs (DI) are used for reading 5-40V DC voltage pulses generated by various binary devices such as digital lightning switches, motion sensors, digital measuring devices (energy meters, flow meters, pressure meters) etc. Digital outputs of the M403 model also feature an in-built pulse counter.
Digital outputs (DO) are using 5-50V DC voltage pulses at 750mA max. current for switching various two-state devices such as door locks, shutter controls, automatic doors, heat pumps, lights etc. Digital outputs of Neuron controllers also feature the PWM (Power Width Modulation) function, allowing the output to transmit analog signal via binary modulated signal.
Relay outputs (RO) are using AC/DC voltage or current for switching two-state devices such as boilers, water heaters, electric motors or larger external relays. Neuron line relays are rated for max. 250V DC/30V AC voltage or max. 5A switchable current.
Analog input (AI) reads 0-10V DC voltage signal or 0-20mA current signal. On the M403 model, analog input can be used for precise current or voltage measurement based on current AI register settings.,
Analog output (AO) serves for regulating and controlling of various devices (three-way valves, heat exchangers, circulation pumps etc.) by 0-10V voltage or 0-20mA current signal. Analog output on the M403 model allows the user to set output voltage or current through corresponding AO register settings.
More detailed info about I/O usage and settings can be found in Neuron technical documentation (see Files tab above)
By standard, all Neuron-line controllers (except the Neuron 500 line) feature a single RS485 serial line for communication with external devices or connection of extension modules (such as Neuron xS series) using the Modbus RTU protocol. A single RS485 can communicate with up to 256 devices.
Included is also a single 10/100MBit Ethernet port for network communication and a single 1-Wire bus for connection of various 1-Wire sensors (such as digital thermometers). A single 1-Wire channel can communicate with up to 15 sensors at once.
Due to 1GB RAM and a 1.2GHz quad-core CPU, all Neuron models possess a very low response rate (ie. delay between input signal reception and output response) of approximately 0.5 ms, giving them a high level of performance.
All components are encased within a durable anodized aluminium case providing IP20 cover. The unit's size is 8 DIN modules, DIN rail holder is included in the package.
Neuron is CE and EMC tested and is compliant with all corresponding European PLC standards. In accordance with these standards Neuron can be used in:
The EU declaration of conformity can be found in the Files tab (see above).
Standard Neuron model overview
|Type S (size on DIN rail: 4 modules = 7 cm)||
4 × 1.2 GHz CPU
|Type M (size on DIN rail: 8 modules = 14 cm)|
|Type L (size on DIN rail: 12 modules = 21 cm)|
Extension modules (size on DIN rail: 4 modules = 7 cm)
Extension modules communicate over Modbus. It is possible to connect them to the control unit via RS485 interface. Extension modules are compatible with any control unit with the RS485 interface and Modbus support.
* features an integrated wireless GPRS module.
** features an integrated TR-76D smart IQRF transciever
Technological specification of the product
Guide to set up and use this device, technological documentation
Modbus register map
Table overview of Modbus registers
Declaration of conformity
Regulatory Compliance and safety information added to each unit
|Dimensions||140 mm × 90 mm × 60 mm|
|CPU||4 × 1 GHz|
|1-Wire bus||Yes (with galvanic isolation)|
|Power||24 V DC|
|RTC backup||maximum 7 days|
|Mounting||DIN (35 mm)|