Interface adapter SI13u

The SI13u converter connects a USB interface to the RS485 2-wire interface. Due to the small dimensions of the housing and the low energy consumption of the SI13u, it is ideally suited for stationary use on PCs as well as for mobile use on notebooks.

The SI13u is connected to the USB interface of the PC or notebook via a roughly 90 cm long cable. The RS485 interface is equipped with a 9-pin sub-D socket. A connection to FELLER ENGINEERING controllers is possible via an RS485 data cable, e.g. AU067.

The SI13u automatically switches direction between sending and receiving. It switches to send mode if a telegram is to be sent via the USB interface. When the transmission is complete, the SI13u is automatically ready to receive. Optocouplers on the device provide galvanic separation between the computer and the peripherals. The RS485 level conversion is performed by a driver module whose electrical properties comply with the EIA RS485 standard. Three light-emitting diodes in the SI13u housing indicate the operational readiness and the data flow direction on the TxD and RxD lines. Power is supplied via the USB cable from the PCs or notebooks. An external power supply is therefore not required.


450mW (5V/90mA)






max. transmission speed

till 115.200 Baud

max. cable length

1.000m (at 9.600 Baud)



ca. 100g (incl. USB cable)

Dimension L/D/H

105 x 43 x 21mm (without connector)

Supported Operating System


7, 8, 10

Information material

Data file
SI13u Product Information
Interface adapter