Owner's manual

4.3.4B Terminal Server (continued)

Server Type: In most cases the iServer will be acting as a Slave device. Slave option is

chosen when a network host needs to connect to the serial port of the iServer (default is

Slave). With RS485 connection, the Host option is selected if the connection is initiated

from the serial device targeting a node on the network.

Number of Connections: The range is from 0 to 5.

If 0 is selected, the Terminal Server feature is disabled. This means that no network

connection can be made to the serial port of the iServer.

If 1 is selected, only one network connection can be made to the iServer’s serial port.

Any number more than 1 would allow the network hosts to monitor (read only) the traffic

on the iServer’s serial port simultaneously, but only one network host would be allowed

to read and write (default is 5).

Local Port: This is the port or socket number for the iServer’s serial port. Any number

between 500 and 9999 can be defined with the exceptions of 1000 and 2002 which are

already used by the iServer for other purposes (default is 2000.)

Port number 502 is the default socket number for Modbus/TCP protocol. If Modbus/TCP

is enabled in the iServer, it’s then suggested to use 502 for the Local Port unless your

host software that supports Modbus/TCP indicates otherwise.

If your application software is IP enabled, it means that it can open a connection

to a node on the network (i.e. iServer with the attached serial device) with an IP

address and a port number.

In some cases the application software may not allow you to specify the iServer’s

port number (it only allows you to enter the iServer’s IP address). In these cases,

you should put 23 in the Local Port field of the iServer. By doing this, the iServer

will forward connections that are made to its Ethernet port directly to its serial port.

Connection Control: Some serial devices accept connections or disconnect

connections based on certain signal conditions.

For example: a serial device may accept a connection only if the incoming DTR signal

(connected to device’s DSR or DCD) is high or low. In this case, when the iServer

receives the TCP connection, before it forwards it to its serial port, it must raise its DTR

(DTR+) or to lower its DTR (DTR-). The iServer is capable of doing this with any of the

hardware or modem control signals (DTR, DSR, DCD, RTS, and CTS).

"Reconnect" is one of the options in the Connection Control menu. This option

can be used in the Serial Tunneling described in Section 4.11. If the connection

in Serial Tunneling is broken due to network problems, power failure, etc., the

Reconnect option will try to get the connection back on line every whatever the

"Connection Timeout" is set to.

For example: if the Connection Timeout is set to 1000 x10 ms or 10 seconds,

then every 10 seconds the iServer attempts to reconnect and reestablish the

serial tunnel to the other network node.

Device No.: Refer to Section 4.3.1

4.3.4.C Remote Access (Tunneling)

Remote Access: This option needs to be enabled when Serial Tunneling is configured.

The Serial Tunneling is explained in detail in Section 4.11.

Changes made in the iServer’s Configuration page can be saved permanently

by pressing the Save button.

Pressing the Reset button will set all the fields back to their default values.