Specifications

C E N T A U R U S P R I M E
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device to reliably transmit data over long distances (up to 4000 feet). The CS485 has
many features not normally found in typical line drivers, and is intended for operation
in harsh industrial environments.
You must also modify the GATEWAY.INI file to specify the baud rate and parity of
the Modbus/RTU connection. All Centaurus Prime Gateways act as a series of
Modbus slaves, and can be a large number of logical devices, but it acts as only one
electrical device on the Modbus/RTU trunk. The Gateway can act at any baud rate
from 4800 baud to 38400 baud (38400 baud is not recommended except for very short
distances). Even, Odd, and None are the valid parity options.
The CS485 may be used in point-to-point applications as well as multi-drop
applications using either 4-wire or 2-wire configurations. Up to 32 devices may be
connected together on one communication line.
The CS485 has 1500-volt optical isolation between the RS-232 side and the RS-485
side. The RS-485 lines are protected with 2 stages of surge protection, and jumpers
allow complete configuration of terminating and pull up/down functions.
Configuring the CS485
The full manual for the CS-485 is available on the Centaurus Prime web site
(www.centaurusprime.com). While it is very lengthy and technical, we recommend
that you download and review the full manual if you are using the Gateway in unusual
applications (e.g., with radio modems, Ethernet converters, line-drivers with delays,
etc.) The CS-485 allows for many options, and a unique “data mode” that no other
RS-485 converter on the market has. It is extremely robust and adaptable.
The CS485’s default configuration is for 2-wire RS485. Following are setup parameters
for RS485 (2 wire), RS422 (4 wire), and optionally, RS232:
RS-485 RX and TX Jumpers
J4 – Enable pull-up resistor for RX+ line
J3 – Enable pull-down resistor for RX- line
J2 – Terminate RX pair with 120-ohm resistor
J7 – Enable pull-up resistor for the TX+ line
J6 – Enable pull-down resistor for the TX- line
J5 – Terminate TX pair with 120-ohm resistor
J8 IN Enables 2-wire operation for both RX and TX pairs
(Dual port operation)