IP Relay – 2x relay + RS-232 / Ethernet converter
HW group
June 2006
www.HW-group.com
Page 5 / 28
Connection topology
•
TCP/IP - NVT
After powering up, the device listens on the given port and awaits TCP client connection.
When the client connects, data from the Ethernet are sent to the serial line and vice versa.
If the client is not connected and data are coming from the serial line, they are stored in a
buffer (cca 16 kB) and transmitted immediately after establishing a connection.
Both relays can be controlled by NVT type M2M protocol. The protocol extends the
implemented RFC 2217 (controlling the serial port via Ethernet). The device does not
have a WWW interface. To control the device you can also use a
IPRC program
,
Hercules Utility or programmer examples for JAVA, Delphi, Borland C++, Visual Basic,
PHP and others.
TCP/IP Client/Server
mode - IP Relay keeps the TCP server function but when any data
are received from the serial line, it is stored into the buffer, the IP relay switches into a
TCP Client mode and tries to establish a TCP connection on the predefined IP address of
the opposite side.
•
HW VSP
With the help of HW VSP (version 1.9 and higher) you can create a virtual serial port (e.g.
COM 5), which will be redirected to a relay’s RS-232 port. Both output relays are then
controlled from the “IP Relay” tab of the HW VSP program.
•
UDP
UDP connection allows the data transfer to the RS-232 only, not controlling the device