The device server may be used in a number of ways to provide Ethernet-to-serial connectivity. The following examples show how you might set up the device server for various applications.
Connect Peripherals to a Windows Host
Using Systech's NativeCOM software in conjunction with the device server allows Windows applications to access these serial ports via the standard Windows COM port interface. This makes the device server’s serial ports almost indistinguishable from the standard serial ports found on the back of most PCs. In RS-232 mode, the DB9 ports also have the same connector pinouts as standard PC serial ports, so that virtually any serial device that can be attached to a local PC serial port can be easily moved to a remote Systech device server port.
Using the serial ports on the device server allows you to add more serial ports to your Windows host and to physically locate those serial ports anywhere your TCP/IP network reaches. You can locate your serial devices on your local network, across a WAN, or
anywhere on the Internet. Using NativeCOM, your Windows-based server can use standard Windows COM port devices (e.g. COM3, COM20, etc.) to access device server serial ports located all over the world.
To set up a device server to work with NativeCOM, just give it an IP address (and optionally set the netmask and gateways). NativeCOM takes care of the rest. Refer to the NativeCOM documentation from Systech for information on setting up NativeCOM ports on the host computer.
Connect Peripherals to a Unix Host
Systech's RTN utility allows you to create pseudo-tty ports on your Unix host system that connect to serial ports on device servers. This is similar in function to NativeCOM for Windows systems. The primary difference is that RTN does not support controlling the physical characteristics of the port (baud rate, character size, parity, stop bits and flow control). Once configured, you can use the pseudo-tty device for logins or open it like other tty devices.
To set up a device server to work with RTN, give it an IP address, and optionally set the netmask and gateways. Then use the Serial Settings web page on the device server to set up the physical characteristics of the port. Require DCD to Use Port should not be selected
(the default value). Refer to the RTN documentation from Systech for information on setting up RTN on the host computer.
Setup a Terminal or Modem to Connect to a Host
You can setup the device server to automatically connect a terminal or dial-in modem to a host on your network. This allows you to set up network-based terminal connections to Unix hosts or other terminal based applications such as Pick.
To set up a device server to do this, use the Serial Settings page to set up the physical characteristics of the port, and use the Port Services page to specify the host connection information. You can specify a fixed IP address to connect to, or you can configure the telnet client to prompt the user for the IP address each time it connects.
If you are setting up a terminal, you may want to select Require DCD to Use Port and Wait
for Keyboard Hit on the Port Services page. If you are setting this up for a dial-in modem,
select Require DCD to Use Port on the Port Services page.
Ethernet-based Serial Multiplexer
You can connect two serial devices to each other through a pair of device server serial ports across a TCP/IP network. To do this, set up one device server to use an outgoing connection to connect to the other device server set up for an incoming connection.
For example, say you have a terminal attached to a local device server at address 192.168.1.1 and you have a device attached to a remote device server at address 10.10.10.1. To configure the multiplexer:
1. Make sure that both device servers have been configured with the proper network and routing information (see Network Settings and DNS Settings).
2. On the local device server, use the Serial Settings page to set up the physical characteristics of the port.
3. On the local device server, use the Port Services page to specify 10.10.10.1 as the
Destination IP Address, 8001 as the Destination TCP Port (for serial port 1), set TCP Protocol to “Raw TCP”, select Require DCD to Use Port , and select Quiet Mode.
4. On the remote device server, use the Serial Settings page to set up the physical characteristics of the port.
Now, when the local terminal is powered on (asserting DCD), it will be appear to be physically connected to the device attached to the serial port at the remote site.
Ethernet-based Console Server
You can use one or more device servers to give virtual access to devices that have serial consoles, such as routers, Unix servers, etc. This allows you to monitor multiple consoles from a single terminal or from a remote location.
To set up a device server to attach to a serial console, give it an IP address, and optionally set the netmask and gateways. Then use the Serial Settings page on the device server to set up the physical characteristics of the port. Require DCD to Use Port should not be selected (the default value).
You can now use telnet on a host computer to connect to the serial console. For example: telnet 192.168.1.1 9001
Replacing a Dial-Up Modem Connection
You can replace a pair of dialup modems with a pair of device server serial ports connected via TCP/IP. To do this, set up two device servers to communicate using modem emulation. For example, say you have a device at a remote site that dials a local server, and you want to replace this with a TCP/IP connection. You install a remote device server at address
10.9.22.1 and a remote device server at address 192.168.40.2. To configure the connection: 1. Make sure that both device servers have been configured with the proper network
and routing information (see Network Settings and DNS Settings).
2. On the local device server, use the Serial Settings page to set up the physical characteristics of the port.
3. On the local device server, use the Port Services page to enable modem emulation. 4. Make sure the server is configured to accept incoming calls, either by issuing the
‘ATA’ command after receiving a ‘RING’ response code, or automatically by setting register S0 on the device server to a non-zero value.
5. On the remote device server, use the Serial Settings page to set up the physical characteristics of the port.
6. On the remote device server, use the Port Services page to enable modem emulation. Specify 192.168.40.2 as the Destination IP Address, 8001 as the Destination TCP Port (for serial port 1), set Telnet Mode to “Raw TCP”.
7. Set the remote device’s dialstring to “ATD”(phone number is blank). If this isn’t possible, specify the target IP in the dialstring using one of the following formats: ATD192.168.40.2:8001 (Standard Dotted Quad Notation)
ATD192,168,40,2:8001 (Dotted Quad, using commas) ATD1921680400028001 (Pad each quad to 3 digits)
Now, when the remote device attempts to establish a connection by dialing out, it will be connected via TCP/IP to the server attached to the serial port at the local site.
Accessing the Device Server from a Remote Network
When attaching TCP/IP devices to a local Ethernet network, all that is required for basic communication is to assign an IP address to the network device. However, if your network devices need to communicate with remote networks, you must also configure IP routing information to tell TCP/IP where to send these remote network packets.A remote network is a network that must be reached via one or more routers. To send packets to a remote network, you must configure the following information:
1. IP Netmask: The IP netmask defines how your network is subnetted. See the section
called IP Netmask for more information.
2. IP Routes: The IP routes define where your routers are and when to use them. See