INTRODUCTION
RCS770 is a general-purpose serial converter equipped with a USB port, RS-232 port and two RS-485 ports.
Conversion can be done in all directions. Alternatively, this converter can act as a RS-485 repeater allowing
more RS-485 devices to be used, since one bus can normally hold 32 devices. The two RS-485 ports can be
configured to act as a single full-duplex RS-422 port or a four-wire RS-485 port.
USB, RS-232 and RS-485 sections are galvanically isolated from each other, which will eliminate ground
loops and give more tolerance against disturbances and overvoltages. However, the two RS-485 buses are
not isolated from each other.
If RCS770 is connected to a computer via USB, it creates a virtual serial port that can be used just like an
ordinary port. Every converter has an individual serial number, and the converter will retain the same COM
port number even if plugged into a different USB port on the same computer. This increases reliability.
RCS770 is able to pass various serial protocols, including Nokeval SCL, Modbus ASCII, Modbus RTU, and
HART. The RS-485 direction is changed automatically, no handshake lines are required.
RS-485 bus is attached via screw terminals, avoiding the need to make solder joints on field.
SPECIFICATIONS
USB port
Version:
USB 1.1 or 2.0
Interface chip:
FTDI FT232R
Power consumption: < 200 mA
Connector:
USB-B (A-B cable included)
RS-485 ports
Baud rates
300…230400 bit/s, except
as a repeater 1200…
115200.
Data bits
5…8
Parity
All supported
Stop bits
1, 1.5 or 2 on USB, 1 on
RS-232
Bus length
1000 m max
Devices on bus
max 32 standard devices or
128 1/4 load devices
Load
1/4 load (128 devices of
this kind can exist on the
same bus)
Transmitter enable
Automatic
RS-232 port
Connector:
D9 male (DTE) (null modem
cable for PC included)
Baud rates:
1200, 2400, 4800, 9600,
19200, 38400, 57600,
115200
Handshake lines:
Not controllable, linked
internally
External power supply
Note: external power supply is not necessary when
the USB is used.
Voltage:
8…28 VDC
Current:
<200 mA
General
Dimensions:
70x85x60 mm + connectors
Oper. temperature:
-30...60 °C
Galvanic isolation:
Yes, 2kV AC/DC
EMC
EMC immunity
EN 61326
EMC emissions
EN 61326 class B
2
