Model:U-7485, USB to RS485/422 converter with 7 interface RS485/422

USB to 7 RS485/422 converter, with the communication indicator light, the baud rate of is from 300 bps to 1Mbps adaptive.      U-7485 is used to achieve the conversion from one USB port to seven RS485/422 interfaces, therefore expanding one computer USB port to seven RS485 or RS422 interfaces. The power supply of the product is from the USB port, without the need of any other external power supply. A unique automatic converting and trasceiving technology and automatic baud rate adaptive technology are both adopted in this product. Furthermore it has the characteristics of:  plug-and-play (PNP) for all software, trasceiving enable control, high-impedance state for the standby mode of no data sending, and supporting multi-point communications, all of which are highly different from other similar low-priced products in the market. The product has a built-in circuit that is both anti-static and anti-lightening, and the unique data trasceiving indicator light as well.

The main technical parameter:

1, applicable to PC's USB ports; the operating system: Win98/2K/XP, MAC OS-9 / X, Linux 2.40 and greate 2, powered by USB port, and no external power is needed; the working current <350 mA 3, outputs are the connecting terminal two-line half-duplex RS485 interfaces and four-line full-duplex RS422 interfaces 4, communication line is the unshielded twisted-pair cabling of which the sectional area is over 0.5 mm25, the largest communication distances are 3,000 meters (4800 bps), 2000 m (9600 bps), 1,000 meters (115.2 Kbps) 6, the number of group site is 32 points at most7, communications rate of 300 bps ~ 1Mbps, standard baud rate adaptive 8, support the UART data format: data bits: 5,6,7,8; stop bit: 1,1.5,2, check in bits: singular, dual, signs, spaces, no check 9, has a function of transient voltage suppression, and the RS485 port can withstand  the transient over-voltage or lightning of which the power is up to 600 W and the impact of electrostatic discharge around ± 15kV11, The working temperature: -20 ~ 70 12, Dimension (L × W × H): 275 × 120 × 40

Descriptions of various parts of above illustration: PWR: power indicator light; USB: USB-B-type socket; Tx: Transmitting data indicator light; Rx: receiving data indicator light, K: selector switch between RS485 and RS422; COM A ~ G: connecting terminal of RS485/422 interface.

The definition of  COM A∼G  RS485/422 connecting terminal signals

Signal Name	Description
RXD+/D+	RS422 signal positive receiving or RS485 negative signal
RXD-/D-	RS422 signal negative receiving or RS485 negative signal
TXD+	RS422 signal positive receiving
TXD-	RS422 signal negative receiving
SG	Signal Ground

      The location of switch K determines whether to use the second-wire RS485 interface or the four-wire RS422.

Method of U-7485 driver installation:      It is easy and convenient to install the driver of U-7485 interface converter. First connect U-7485s USB port to PCs USB port with the cable sold together with the product, and then the system will prompt the discovery of new hardware, and next what need to be done is just to put the CD-ROM included in the product in the driver following the instruction shown in the dialog. Following the tips given and chose next step for full installation. When the installation is completed, under the Windowss "start menu \ Settings \ Control Panel \ system \ hardware \ Device Manager there will be seven extra new COM ports and the correspondent drivers properties.

      These seven extra new COM ports are extended from the USB port, and they should be selected in the communication software just as using the traditional COM ports.

      For detail of the installation, please refer to "USB to COM driver installation instructions" on the CD-ROM included in the product.

The application of products: 

      The usage of U-7485 is exactly the same as the ordinary RS485/422 interface. When the switch K is in the location "485", the four-wire half-duplex RS485 interfaces D + and D- are used; When the switch K is in the location 422, the four-wire full-duplex RS422 interfaces RXD +, RXD-, TXD + and TXD- are actually used. Its communication distances are up to 3,000 meters (4800 bps), 2000 m (9600 bps) and 1,000 meters (115.2 Kbps).When the length of communication wire is over 50 meters, one terminal resistance of 120 Ohms should be connected in parallel between RXD + / D + terminal and RXD-/D-, and another one should be connected in parallel at bus terminal as well.

Detailed information see the official website of FOURSTAR: fourstar-dy.com

Model:U-7485, USB to RS485/422 converter with 7 interface RS485/422