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RefGuide_U-routerNGW_v1.01.docx
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4.5
Expansion Port Pin Assignments
The U-router NGW supports an expansion port on an RJ11 connector on the front panel. The
expansion port has a low power relay contact on the two middle pins (pin 3 and 4) of the connector.
Pins 2 and 5 of the RJ11 connector are used for an RS485 serial interface in accordance with EIA/TIA-
485 standard. This interface can be used to run a two-wire Modbus protocol or the RFI RIOT protocol.
Pins 1 and 6 are not connected. They may be used in future hardware versions of the U-router NGW.
Figure 7: Expansion port on RJ11 connector
Please note:
The relay is specified for low power devices only. This means that the maximum
ratings are 100V @ 500mA for switching purposes maximum. In case you want to switch higher
voltages and/or higher currents you need to connect an external relay, such as RFI Engineering’s
single port remote power switch; RE.99.R1NC.
