Device Service

A method used to connect a host to a host device port:
Netdata
    Can be used for customized application programs requiring a TCP or clear channel connection directly to the asynchronous port.
  • Programs that use a socket interface (or a similar TCP interface) are provided with a direct data link to the device connected to the PortMaster serial port. No special option negotiation or protocol is required.
  • The default port number for netdata is 6000; you can enter an alternate port if required in the text box next to the Device Service drop-down list. These port numbers can also be pooled.
  • For this service, the Device Name must be /dev/network.
PortMaster (Default). When selected, the port is accessed through a /dev/tty device on the UNIX host. For this service, the PortMaster daemon in.pmd must be on the login host. PortMaster is the preferred service because it allows the port to operate like a serial port installed on the host.

For this service, the Device Name setting must match a host device name listed in the /dev directory of each UNIX host with access to the shared device.

Rlogin Supported by many UNIX hosts, this service can be used to allow hosts on the network to initiate an rlogin session to the PortMaster. Once the session is established, a host application can directly read and write data to the asynchronous port.

If multiple ports on the PortMaster are configured to use this service, a pool of ports that can be accessed by other hosts is automatically created. When all ports are in use, new users receive a Connection Refused message.

Telnet Supported by most TCP/IP hosts, this choice allows many different types of computers on the network to initiate a telnet session to the PortMaster. Once the session is established, the host application is able to directly read and write data to the serial port.

For this service, the Device Name setting must be /dev/network.

The default TCP port number for telnet is 23; but you can enter an alternate TCP port if required in the text box next to the Device Service drop-down list. These ports can be pooled.

Note - Move the telnet administration port to a different number if 23 is used for network devices in this manner.