Using the MSS
Host-Initiated Connections
5 - 3
5.1.2 LAT Connections
Most VMS applications require the creation of a LAT application port to
access the MSS serial port. Programs can use the LAT application port as
they would use a physical port for input and output. For example, an
application might be configured to use port LTA3419 which would allow
it to access a device connected to the MSS serial port.
To configure LAT on your VMS host, create a new and unique application
port using the host’s LATCP program (in Figure 5-3, LTAnnnn represents
any unused LAT port number). Map the application port to the MSS by
specifying the MSS node name and the serial port name. Enter the
following commands at the VMS prompt:
Figure 5-3:
Creating a LAT Application Port
NOTE:
The procedure is similar for DEC UNIX LAT.
If heavy input or output loads are expected on the LTA port, you can set
alternate type ahead to reduce flow control on the ports.
Figure 5-4:
Reducing Flow Control
To connect to the MSS serial port from a VMS host, use the command
below and include the appropriate LAT application port number:
Figure 5-5:
Connecting to the MSS
$ RUN SYS$SYSTEM:LATCP
LCP> CREATE PORT LTA
nnnn/APPLICATION
LCP> SET PORT LTA
nnnn/node=mssname/port=port_1
LCP> SHOW PORT LTA
nnnn
LCP> EXIT
$ SET TERM/PERM/ALTYPEAHD LTA
nnnn
$ SET HOST/DTE lta
nnnn