GDSX Manual

Operations and Support
Extended General Device Support (GDSX) Manual–134303
3-10
Running GDSX as a NonStop TS/MP Server
The MAXLINES configuration parameter indicates to GDSX that there is to be a
maximum of one line in the configuration.
Then SCF must be used to configure the LINE and devices under the line, and to
START the LINE. Here is an example of a configuration having one LINE and three
SUs under the LINE:
-> SCF
-> ADD LINE $GDSX.#LINE1, ACCESSNAME $IOP1
-> ADD SU $GDSX.#LINE1.DEV1
-> ADD SU $GDSX.#LINE1.DEV2
-> ADD SU $GDSX.#LINE1.DEV3
-> START LINE $GDSX.#LINE1
When the LINE is started in SCF, GDSX refers to the line’s access name (the file
associated with the LINE object), opens the file ($IOP1 in this case), and creates a
LINE^HANDLER task to manage communication with the devices on the line. All
devices on the LINE are then available for access.
In PATHCOM, you configure SUs that Pathway/TS is to open through GDSX. For
example, if a Pathway/TS requester is to communicate through a GDSX process named
$GDSX with a subdevice DEV2 configured under line $LINE1, the file name
$GDSX.#LINE1.DEV2 is used in a series of PATHCOM commands like the following:
= SET TERM TCP TCP-X
= SET TERM TYPE T16-6530:0
= SET TERM INITIAL LOGON-SCREEN
= SET TERM FILE $GDSX.#LINE1.DEV2
= ADD TERM TX-2
A session or thread is established when you issue the following PATHCOM command:
= START TERM TX-2
Then the TCP opens the file specified in the configuration commands,
$GDSX.#LINE1.DEV2 in this example. The GDSX process receives the open message,
derives the name $LINE1.#DEV2 from the message, determines from configuration
information previously entered with SCF that DEV2 is configured under line $LINE1,
and establishes a thread from the TCP requester through $GDSX to the line $LINE1 and
then to device DEV2.
Running GDSX as a NonStop TS/MP Server
You can configure a GDSX application to run as if it were a NonStop TS/MP server.
Running an application as a server has two benefits:
•
If the GDSX server is not running in NonStop mode and it fails, NonStop TS/MP
automatically restarts it if the server is configured with the NonStop TS/MP
AUTORESTART parameter set to a value equal to or greater than 1.
•
A GDSX server is affected by the PATHCOM commands that deal with servers,
such as THAW and START. (The PATHCOM commands FREEZE or STOP affect
a GDSX server when only Pathway/TS requesters have opened GDSX. If processes
outside of the NonStop TS/MP or Pathway/TS application have also opened a
GDSX server, a FREEZE or STOP command does not affect the GDSX server.)