CIRCUTOR Measuring instruments

background image




The TCP1RS+ is a communications gateway that
converts the Ethernet physical environment to RS-
485 serial communications.

This document provides the instructions for use and describes

the operation of the TCP1RS + device. If misplaced, the

manual may be downloaded from the CIRCUTOR web site:

Disconnect the device from the power
supply source before undertaking any
maintenance, modification of connections,
repairs, etc. If you suspect an operational

fault in the unit or in its protection system, remove the
unit from service. The design of the unit makes it easy
to replace in the event of a fault.


The TCP1RS+ device is a serial physical
environment to Ethernet communications converter
that uses TCP/IP communication packages. The
gateway is responsible for the transparent conversion
under TCP or UDP connections. The operation is
determined by the parameterisation carried out in the
internal configuration web menu.


The device is equipped with a self-detecting
10BaseT / 100Base TX connection for the physical
connection of the TCP1RS+ converter to an Ethernet
network. For its configuration, the device has an
internal web site from which the user can define the
network protocol used to communicate with the
management software or communications system

2.1.- Ethernet addressing

As the unit is connected to the master
communication system by means of an IP
connection, the addressing parameters must be
configured. The configuration modes include the
assignment of a fixed IP or configuration of a DHCP

2.1.1.- Ethernet address assignment

To configure the IP address configuration in any of
the available formats, run the IPSetup.exe
executable supplied with the unit.

2.1.2.- Fixed IP assignment

Run IPSetup and select the TCP1RS+ converter. To
assign the fixed IP address, enter the MAC address
shown on the permanent side label attached to the
device, the format of which is 00:26:45:XX:XX:XX.

In the IP Address field, enter the IP address being
configured; do the same with the Netmask and the
Gateway if necessary. After entering the device
configuration, press “Configure” to send the
configuration to the unit.

2.1.3.- DHCP IP assignment

To assign the DHCP name, activate this option by
clicking on the DHCP checkbox. Once the
configuration fields have been enabled, enter the
MAC address that can be seen on the permanent
side label attached to the device, the format of which
is 00:26:45:XX:XX:XX. In the Address, field, enter a
free temporary IP address, which is within the
working range of your computer.

2.2.- Configuration

Once the unit is connected to the Local Area
Network (LAN) and the IP address is configured or in
the DHCP mode, the remaining configuration can be
established in the IPSetup software console. When
the unit has been fully configured, the configuration
can be sent by clicking on “Configure”.

2.2.1.- Network protocol

The unit can be connected to the master
communications system by means of three types of
network protocols and to a configurable port (TCP,
UDP or Modbus/TCP).

2.2.2.- Configuration of the Serial port

The communication parameters of the serial bus are
fully configurable in terms of baud rate (1.2 bps to
115.2 kbps), data bits (7 or 8), parity (none, odd or
even) and stop bits (1 or 2). The data will be
configured by default to 8 by selecting the
Modbus/TCP communications protocol.

2.2.3.- Device information

When the unit is connected with IPSetup, the top
part of the screen shows the firmware version and
the machine address of the device (the same
address as that shown on the permanent side label).

2.2.4.- Save changes

Once any change has been made to the
aforementioned sections, the information must be
saved using the “Configure” option. If you wish to
return to the default configuration, select “Load

2.3.- Configuration of network protocols

2.3.1.- TCP Protocol

In the TCP/IP protocol stack, TCP is the intermediate
layer between the Internet protocol (IP) and the
application. In general, applications need reliable
communications. The IP layer offers an unreliable
datagram service (no confirmation), so the TCP adds
the functions required to offer a secure, error-free and
zero loss service for the communications between
two systems.


Protocol: TCP Mode


Port: Destination TCP Port number

2.3.2.- UDP Protocol

User Datagram Protocol (UDP) is a minimum
transport level message-oriented protocol that has
been documented in the RFC 768 of the IETF.
In the Internet protocol family, UDP provides a simple
interface between the network layer and the
application layer. UDP does not offer guarantees for
the delivery of its messages and the UDP origin does
not withhold the states of UDP messages sent to the
network. UDP only adds the multiplexing functionality
to the application and the verification sum of the
header and useful load. Any type of guarantees for
the transmission of information must be implemented
in higher layers.


Protocol: UDP Mode


Port: Destination UDP Port number

2.3.3.- Modbus/TCP Protocol

Modbus/TCP is a variation or extension of the
Modbus® protocol, which enables it to be used on the
TCP/IP transport layer. Therefore, Modbus/TCP can
be used throughout the Local Area Network or the
Internet. This was one of the objectives that
motivated its development (the specification of the
protocol was submitted to the IETF, Internet
Engineering Task Force).


Protocol: Modbus/TCP Mode


Port: Fixed port number 502

2.3.4.- Tx Delay Rx Time

The TCP1RS+ converter uses two communication
parameters to control the Modbus frames on the
RS485 bus.


Tx Delay: additional delay of the RS serial bus


Rx Time: maximum bus waiting time

Table of contents