Application example for the serial Com-Server:
Running ESPA communication over TCP/IP networks
ESPA protocol has become established as the standard for sending short messages and information. Typical applications include fire alarm systems, alarm servers, building management systems, telephone systems, light signaling systems and much more.
One very common application is nurse and staff call systems in hospitals and care facilities.
Physical transmission is in the form of serial data communication, based on RS232, RS422 or RS485. ESPA allows for both point-to-point connections and bus systems with multiple communication partners (RS485).
One disadvantage is that dedicated cable networks are needed for ESPA systems. The resulting effort and expense especially with spatially extended systems.
By using the W&T Com-Server you can carry ESPA connections over the normal Ethernet network as well. No matter whether using ESPA as RS232, RS422 or RS485, the Com-Server++ supports all three physical standards.
Tunneling ESPA through the network - how it’s done
To tunnel the ESPA protocol two Com-Server++ 58665 are required.
Preparations
- Connect both Com-Servers to the network and apply power
- Prepare serial wiring and set DIL switches to the appropriate physical transmission version
- Assign an IP address to both Com-Servers
Configure serial parameters
Both Com-Servers must have the serial parameters for the ESPA system set, including baud rate, parity, number of data bits and stop bits.
From a browser enter as an address the IP address for the respective Com-Server and log in with an Admin password (factory default is no password)
Then click on the link SETUP Port 0 (Serial) and then select UART Setup.
The settings must be transmitted using Send.
Configure Com-Server 1 as Box-to-Box Master
Determine the Com-Server close to the ESPA Master as a Box-to-Box Master.
Select menu branch SETUP Port 0 (Serial) >> TCP/IP Mode >> Box to Box.
For Slave IP-Address select the IP address of the second Com-Server and for Slave Port select 8000 
Com-Server 2 as Box-to-Box Slave
For the second Com-Server only its own IP parameters and the serial parameters need to be configured.
The Box-to-Box master simply opens the connection, after which the tunnel can be used for sending the ESPA data.
