M5Stack Single-phase DC SSR Unit (CDG1. 1DD-10A)

M5Stack Modbus 10A DC Solid-State Relay Unit

M5Stack Modbus DCSSR Unit combines an ESP32-C3 control board with a DC-to-DC single-phase solid-state relay for switching compatible DC loads. It supports three control paths: a local button, I2C slave operation, and Modbus networking. A programmable RGB indicator provides visible status feedback, while the RS485PWR interface supports device power input across the specified 9–24 V range.

Choose the Correct DC Load Before Wiring

M5Stack Modbus DCSSR is designed for DC-to-DC switching, not as a general replacement for AC solid-state relays. The relay supports a DC 24–220 V load-voltage range and a 10 A current rating. Confirm load type, operating voltage, steady current, startup current, inductive behavior, heat dissipation, conductor size, protection, and enclosure safety before installation.

Switch Locally with the Built-In Button

M5Stack Modbus projects can use the button for direct local control during setup, demonstrations, service checks, or simple standalone switching workflows. Local control is useful when a technician needs to verify relay behavior without first establishing a network connection. The exact operating procedure should still prevent accidental switching of connected machinery or energized loads.

Integrate as an I2C Slave

M5Stack Modbus DCSSR also provides I2C slave control at address 0x50. This path suits compact embedded systems where a nearby host controller already manages sensors and actuators on an I2C bus. Plan bus addressing, cable length, electrical noise, and shared power carefully, especially when the switched load can create transients or interference around the control electronics.

Network Multiple Devices with Modbus

M5Stack Modbus support is useful when relay control must fit a more structured industrial or distributed communication layout. The RS485PWR interface can simplify deployments that need both communication and device power routing. Define device addressing, polling intervals, timeout behavior, retry limits, and safe fallback states before connecting the relay to equipment that must respond predictably to communication loss.

Plan Relay Loading and Thermal Margin

For both resistive and inductive loads, plan continuous operation around 50% of the relay rating and verify thermal margin under actual conditions. M5Stack Modbus system design should avoid treating the headline 10 A value as a universal continuous operating target under every thermal and load condition. Consider enclosure temperature, switching frequency, load profile, wiring, cooling, and the difference between steady current and surge current.

Account for Leakage and On-State Voltage Drop

M5Stack Modbus DCSSR has off-state leakage current up to 5 mA and an on-state voltage drop up to 1.6 V. These characteristics matter when controlling sensitive loads, low-power circuits, or equipment that may react to small leakage currents. Validate the actual connected load rather than assuming the output behaves like an ideal mechanical contact.

Use Solid-State Switching for Repeated Control

M5Stack Modbus DCSSR fits DC load switching, lighting control, motor-related control, industrial automation, and remote power management within the specified electrical limits. Solid-state switching can support repeated operation without mechanical contact wear, but correct load protection and thermal design remain essential.

Integration and Commissioning Workflow

Start with the control side before connecting the final load. Verify button behavior, I2C address 0x50 when used, Modbus communication when used, RGB status logic, and safe startup state. M5Stack Modbus debugging is easier when communication tests are separated from high-energy load tests. Add the real load only after control behavior is stable and documented.

M5Stack Modbus installations should include an explicit response for power restoration, communication loss, controller reset, and unexpected network interruption. Decide whether the relay must remain off, restore a previous state, or follow another controlled policy. Test that behavior under actual restart conditions rather than relying only on normal command sequences.

Development Resources

Use technical documentation for pinout, protocol, wiring, and electrical details.

• Technical Documentation

M5Stack Modbus relay systems are easier to maintain when load specifications, wiring diagrams, device addresses, firmware versions, fallback behavior, switching limits, and commissioning results are recorded before equipment is duplicated or deployed.