We are thinking of using off-the-shelf terminal servers for SCADA FEP's failover/switching. But we wonder:

1. Is there a terminal server which could let you take over a port no matter the port has been allocated by another machne ?

2. IS there a terminal server which has two independent ethernet ports so if a machine at one ethernet port is going down, the other can take over the serial ports ?

Jim Y Cai

 

see lantronix.com...they have rs232 to tcp/ip converter, which solves your problem

 

> 1. Is there a terminal server which could let you take over a port no
> matter the port has been allocated by another machne ?

Make sure the terminal server supports a remote-shell user interface or SNMP network management. Generally, you can program in a
remote-shell command to "force a disconnect" on a port. Each terminal server product is a bit different syntax.

> 2. IS there a terminal server which has two indepedent ethernet ports so
> if a machine at one ethernet port is going down, the other can take over
the
> serial ports ?

Ethernet is a sharing medium, so you only need one Ethernet connection.

I have used Lantronix MSS before. They are available from several catalog equipments at about $350 each.

ISA / industrial computer had an ad for a terminal server that mounted on a DIN rail. So they are becoming industrialized.


William F. Hullsiek
Software Engineer