Supported Devices

Device Type	Variants	Modbus TCP (Ethernet)	RS485
DDSU666	230V-5/80A 230V-100A/40mA	✅	✅
DTSU666	3x230V/400V-5/80A 3x230V/400V-1.5(6)A 3x230V/400V-100A/40mA
DTSU666HW

Connection

The communication between the SmartgridOne and the energy meter operates via an RS-485 serial bus or Modbus TCP.

It is recommended to use shielded cables with twisted pairs for optimal performance. For short distances, a twisted pair from a network cable (minimum CAT5e) can be used.

The following guidelines apply:

• Maximum Distance: The total cable length, including the main cable and branches, is limited to 100 meters.
• Connecting Multiple Energy Meters: The cable should be daisy-chained from meter to meter or branched off the main cable (branches must not exceed 1 meter).
• Long Distances: It is recommended to install a 120Ω termination resistor at the end of the main cable and activate the termination resistor on the SmartgridOne Controller.

RS485 Wiring

• For correct RS485 wiring: Follow the guidelines for RS485 wiring.
• If the wiring shown in the table below is incorrect, please let us know.
• There is no general consensus in the industry about the usage of A and B for the RS485 polarity, so it may be counterintuitive and opposite of what you might expect for some devices.

Device	SmartgridOne Controller model OM1	SmartgridOne Controller model IG8	RS485-USB converter	RS485-Ethernet converter
Terminal 24	RS485 A	RS485_POS	RS485 A	TX+
Terminal 25	RS485 B	RS485_NEG	RS485 B	TX-
N/A	RS GND	GND	Not available	G

NOTE: RS485 Device Addresses

• You MUST give each device on the RS485 bus a unique address. Check the manual of the device on how to do this.
• Use lower addresses first (1, 2, ...) because the SmartgridOne Controller will find them faster!
• For each device, it is generally recommended to stick with the factory default baud rate, parity, and stop bits. The SmartgridOne Controller will scan on those first.