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USB-485 Isolated USB-RS422/RS485 Interface Converter
Installation and Operation
General
The USB485 is a general purpose USB to RS422/RS485 isolated interface converter. It is intended to provide an
RS422/485 port on a PC which has only a USB port available. Drivers are included to create a virtual COM port
within the operating system, compatible with standard Windows application programs. The isolation barrier is
between the USB interface and the RS422/485 (DB9) interface.
Installation
1.
With Windows running, insert driver CD into computer's CD drive
2.
Connect USB connector to computer USB port
3.
Windows should report that a new device has been found, offering a choice of locations to look for the
driver. Choose the CD as the location.
4.
Windows should now install the driver. Now you need to find out which COM port number has been
allocated: open up Control Panel / System / Hardware / Device Manager (the exact location varies with
Windows version) and look under Ports (COM and LPT). The device should appear as "FT232" or "FTDI"
or similar.
5.
Configure your application software to use this COM port number.
6.
Unless running in a 4-wire half-duplex application, you will need to configure the RS422/485 port for the
correct driver and receiver enable modes. This involves bridging some pins on the DB9 connector as
shown under Connections.
Note: The USB-485 contains a unique USB device ID which ensures that whichever USB port it is plugged into, it
always appears under the same COM port number. Usually, this is the desired behaviour for application software
Configuration reasons. However, it has two side effects:
(1) If you are going to be using multiple USB-485 converters on one PC, Windows will ask for the CD to be inserted
for the installation of each one - because it thinks each one is a different device. In this case, copying the CD
contents to a suitable folder on the PC and pointing the "new hardware found" function to that folder will save time.
(2) If you want the converter to always appear under the same COM port number, you need to always use the one
specific USB-485 converter. If you plug in another USB-485 converter (even into the same USB port) it will appear
under a new COM port number.
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Related Manuals for KK Systems USB-485
Summary of Contents for KK Systems USB-485
- Page 1 However, it has two side effects: (1) If you are going to be using multiple USB-485 converters on one PC, Windows will ask for the CD to be inserted for the installation of each one - because it thinks each one is a different device. In this case, copying the CD contents to a suitable folder on the PC and pointing the "new hardware found"...
- Page 2 Connections Pin Function RS4xx DB9 Pin Function Connector Connector USB +5V No Connection -- Data RX-A + Data/Clock TX-B USB Ground GROUND Shield Shield /RXenable (note 1) GROUND RX-B TX-A /TXenable (note 2) Note 1: To permanently enable the RS4xx receiver, connect pin 5 to GROUND Note 2: To permanently enable the RS4xx driver, connect pin 9 to GROUND 2-wire RS485: Interconnect TX-A and RX-A and this gives the "A"...
- Page 3 USB-serial chips on the market: Prolific and FTDI. Most USB-RS232 converters on the market, including the KK Systems USB-232, use the Prolific chip and drivers. Nearly The USB-485 uses the FTDI chip and drivers, so if you are using one of the other converters you will still need to install the new FTDI drivers which are enclosed with this product.
- Page 4 KK Systems for instructions. Alternatively it is usually possible to force the USB-485 driver (under Ports / Properties / Advanced) to use a different COM port number; be sure it isn't used by another device.
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