Revolution Pi Connect S

The RevPi Connect S is an industrial DIN-rail computer built on the Raspberry Pi Compute Module 4S. It combines the openness of Raspberry Pi and Debian Linux with robust 24 V industrial hardware – including an on-board digital input, a relay output and a hardware watchdog. It can act as edge gateway, soft PLC and IIoT controller at the same time. As a cost-efficient member of the RevPi Connect family, it also supports the RevPi fieldbus gateway modules. With the open-source edge agent thin-edge.io, the RevPi Connect S connects to Cumulocity in a few minutes: collect machine and sensor data, monitor device health, and manage software, configuration and logs remotely across your entire fleet.

Reading meters and machines

Two separate RS485 lines let you run two Modbus RTU buses at once, for energy meters, inverters and more.

Connecting your network devices

A built-in switch links up to three Ethernet devices. The fourth port goes to your company network.

Measuring and switch on site

Read a pressure or level sensor, send a setpoint, or switch an alarm lamp with the relay.

Going wireless

Use WLAN where there is no cable, and Bluetooth for nearby sensors.

Service remotely

Update software, change settings and fetch logs from Cumulocity, without a site visit.

Technical Data

• Broadcom BCM2711, quad-core Arm Cortex-A72 @ 1.5 GHz (Raspberry Pi CM4S), passively cooled with heat sink
• 1 GB LPDDR4 RAM, 8 GB, 16 GB or 32 GB eMMC flash
• Hardware Interfaces
  • 2 × 10/100 Mbit/s Ethernet (RJ45, separate MAC addresses)
  • 1 × RS485 (screw-type terminal)
  • 1 × digital input, 24 V control voltage (e.g. power-good signal of a UPS), protected against overvoltage and negative voltages;
  • 1 × relay output, approved up to 30 V switching voltage, max. 2 A @ 30 V DC (resistive load) – optionally controlled by the hardware watchdog
  • 2 × USB-A (max. 1 A in total)
  • 1 × Micro-HDMI 2.0a (4K)
  • 1 × Micro-USB (for flashing the eMMC image only)
  • PiBridge (RevPi I/O and gateway modules)
  • ConBridge (RevPi Con modules)
  • 6 status LEDs (bi-color), 2 of them freely programmable
• Reliability Hardware watchdog (triggers after approx. 60 s, can be disabled), real-time clock with min. 24 h buffer time
• Expansion RevPi I/O modules (digital, analog, relay) and fieldbus gateways (PROFINET, EtherCAT, EtherNet/IP, PROFIBUS) via PiBridge; RevPi Con modules via ConBridge
• Standards ESD, EMI and surge/burst tested per EN 61131-2 and IEC 61000-6-2; CE, RoHS, REACH, UKCA, UL (File No. E494534)

Note: With 1 GB RAM, the device is intended for headless operation. Revolution Pi recommends the Linux desktop GUI only on devices with at least 2 GB RAM.

How the Connection to Cumulocity Works

thin-edge.io is a free, open-source software agent. It runs directly on the RevPi and needs only few resources. Every program on the device can hand over data to it. For example, this can be a Python script, a Node-RED flow or a soft PLC.

• Data: send measurements, events and alarms
• Device management: check device health, restart the device and run shell commands
• Software: install, update and remove packages remotely
• Configuration and logs: fetch and change files from Cumulocity
• Child devices: show connected machines or meters as separate devices
• Remote access: open secure SSH or VNC sessions via Cumulocity Cloud Remote Access

Add Inputs, Outputs and Fieldbuses

The Connect S has inputs or outputs of its own but can even be equipped with expansion modules right next to it. They plug into the system bus on both sides. All values then appear in one shared process image.

• RevPi DI, RevPi DO and RevPi DIO: digital inputs and outputs for machine states, counters, lamps and valves
• RevPi AIO and RevPi MIO: analog inputs and outputs for sensors such as pressure, level or temperature
• RevPi RO: relay outputs for switching higher loads
• RevPi Gateways: PROFINET, EtherCAT, EtherNet/IP and PROFIBUS

Good to know: A gateway does not read the PLC on its own. Instead, the PLC program writes the selected values to the gateway and the data appears in the RevPi process image. Therefore, you need a small change in the PLC project. A script or Node-RED flow then publishes it to Cumulocity via thin-edge.io.–

Please note: Expansion modules have their own temperature ranges. The module with the smallest range defines the range of the whole system.

RevPi Con modules (ConBridge):

All RevPi Con modules can be connected via the ConBridge system bus – e.g. to add further communication interfaces such as CAN.

 

RevPi Connect S, SE, 4 or 5?

Choose the RevPi Connect S if you want a cost-efficient device with RS485, on-board digital I/O and support for RevPi fieldbus gateways.

Choose the RevPi Connect SE if you need the same base hardware but no fieldbus gateways.

Choose the RevPi Connect 4 or RevPi Connect 5 if you need Gigabit Ethernet, more RAM (2–8 GB), optional WLAN/Bluetooth, TPM 2.0, or a local HMI with Linux desktop. The Connect 5 also offers on-board CAN / CAN FD and operation up to +60 °C.

Getting Started in 5 Steps

1. Choose your variant based on eMMC size (see table above), plus any I/O, gateway or Con modules you need.
2. Install and power up: Mount the device on a DIN rail, connect 24 V DC and Ethernet. Configure attached RevPi modules with the PiCtory web tool.
3. Install thin-edge.io on the device:
   curl -fsSL https://thin-edge.io/install.sh | sh -s
4. Connect to your Cumulocity tenant:
   sudo tedge cert create --device-id <your-device-id>
sudo tedge config set c8y.url <your-tenant>.cumulocity.com
sudo tedge cert upload c8y --user <your-user>
sudo tedge connect c8y
   Onboarding options evolve – always check the current thin-edge.io documentation.
5. Send your first data:
   tedge mqtt pub te/device/main///m/environment '{"temperature": 21.3}'
   The device and its measurement now appear in Cumulocity Device Management.

Step-by-step guide: Revolution Pi tutorial: Cumulocity with thin-edge.io

Resources

• RevPi Connect S in the Revolution Pi shop
• Tutorial: Installing thin-edge.io and connecting to Cumulocity

Partner: Revolution Pi (by KUNBUS GmbH, Germany)

Device on Partner Website