Installation
30 Rev. D7 Jul 2017 Marathon MM
6.3 Computer Interfacing
The distance between the sensor and a computer can be up to 1200 m (4000 ft.) via RS485 interface. This
allows ample distance from the harsh environment where the sensing system is mounted to a control
room or pulpit where the computer is located. The USB/RS485 Interface Converter allows you to connect
your sensor to computers by using a USB interface.
With auto configuration the converter is able to automatically configure RS485 signals without external
switch setting. The converter is equipped with 3000 VDC of isolation and internal surge-protection to
protect the host computer and the converter against high voltage spikes, as well as ground potential
difference. When the converter is connected the computer gets one virtual COM port.
Technical Data
Power supply 5 VDC direct from USB port
Speed max. 256 kBit/s
RS485 4 wire (full duplex) and 2 wire (half duplex)
Terminal screwed accepts 0.05 to 3 mm² (AWG 13 to AWG 30)
USB connector type B (supplied with type A to type B cable)
Ambient Temperature 0 to 60°C (32 to 140°F), 10-90% relative humidity, non-condensing
Storage Temperature -20 to 70°C (-4 to 158°F), 10-90% relative humidity, non-condensing
Dimensions (L x W x H) 151 x 75 x 26 mm (5.9 x 2.9 x 1 in)
Figure 7: USB/RS485 Converter (XXXUSB485)
Using the 2-wire communication reduces wiring cost in comparison to the 4-wire communications. The
disadvantage is, that because the data transfer can be only in one direction at the same time, 2-wire
communications have a maximum baud rate of 38.4 kBaud. 2-wire communications is available for
network installations, in situations where other sensors are only able to communicate via 2 wires(e.g.
MI3 sensor).