System information

General Reference Guide eWON Configuration
RG-001-0-EN ver 1.5 eWON® - 20/03/2009 - ©ACT'L sa Page 17
Another feature of the TELNET RFC2217 mode is its ability to change the modem line status. This means that the RTS/CTS, DTR, DCD (etc.)
levels of the eWON’s physical port are reflected to the PC virtual port and vice-versa.
This protocol is called TELNET RFC 2217 because it has been standardized and described in an RFC specification. It means that any client
supporting the RFC2217 protocol can use the eWON as a virtual port server.
3.3.2.1.4 MODBUS/TCP MODBUS/RTU Gateway
Although it is possible to use this technology to transfer almost any type of data through the virtual serial port, some protocols require special
handling for efficient operation. ModbusRTU is one of these protocols and VCOM technology does not apply well to that protocol. For Modbus
RTU communication it is recommended to use the MbsTcpCOM software and use the eWON as a ModbusTCP to ModbusRTU gateway.
3.3.2.2 PC Virtual COM Port driver
There are different options for creating virtual serial ports on the PC side.
3.3.2.2.1 MbsTcpCOM
This software provided by eWON s.a. is used to create ONE virtual COM port on the PC, the virtual COM port must only be used by softwares
that are supposed to communicate on the PC serial port in ModbusRTU.
The ModbusRTU slave is actually connected to the eWON’s serial port. The PC software believes that it is “talking” directly to the device through
its serial port while it actually "talks" to its virtual serial port that transfers all the data to the eWON by translating every requests into ModbusTCP
(without interpreting them).
This software is downloadable for free from http://www.ewon.biz
.
3.3.2.2.2 Serial/IP
Tactical Software provides this software: http://www.tactical-sw.com
This software is not for free. It can be purchased directly from the Tactical software website.
An 30 days-evaluation version is available for download from this site.
The software supports both RAW TCP and Telnet RFC 2217 modes and works on all Windows version from Windows 95 to Windows XP.
The software can create up to 256 virtual serial ports that communicate with multiple eWONs.
3.3.2.3 eWON VCOM Configuration
3.3.2.3.1 Introduction
All serial ports can be used for VCOM.
Depending on the eWON type, you have 1, 2 or 4 serial ports.
The COM1 is always the serial port 1 of the eWON.
The COM2 is always the MODEM port (even if there is no modem present on your eWON, the COM2 exists but is useless).
The COM3, if present, is linked to the serial port 2 (SER2), the full RS-232 port on eWON4002.
The COM4, if present, is linked to the serial port 3 (SER3).
As COM2 is the modem, it should only be used for debug purposes because when the port is used by VCOM it is not available to PPP or SMS
communication.