GDSX (Extended General Device Support) Manual

Operations and Support
Extended General Device Support (GDSX) Manual—529931-001
3-7
Running SCF and Starting Requesters
An example of how Pathway/iTS requesters may be used in a GDSX application is
provided in Running a Pathway/iTS Application on page 3-9
The configuration parameter with external parameter name MAXLINES is used to
specify the maximum number of LINEs that may be configured for the GDSX process.
The default for the parameter is zero. To run GDSX with a LINE, the configuration
parameter must be set to some positive integer less than 15 either by an assignment
within the USER^INIT^CONFIG^PARAMS user exit of the GDSX object file or by a
TACL PARAM command. See MAXLINES on page 2-65.
In a GDSX application with a LINE, there can also be dynamic SUs and preconfigured
SUs. All SUs under a LINE must be preconfigured. SUs not under a LINE can be
dynamic or preconfigured.
When adding SUs under a LINE:
1. Add the LINE.
2. Add the SUs under the LINE.
3. Start the LINE.
Then run the applications that communicate with the SUs under the LINE.
Here is an example of a configuration having a LINE and two SUs under the LINE:
> PARAM MAXLINES 1
> RUN GDSE /NAME $GDSX, NOWAIT/
-> SCF
-> ADD LINE $GDSX.#LINE1, ACCESSNAME $IOP1
-> ADD SU $GDSX.#LINE1.DEV1
-> ADD SU $GDSX.#LINE1.DEV2
-> START LINE $GDSX.#LINE1
> RUN APPL /NAME $A1, OUT $GDSX.#LINE1.DEV1, NOWAIT/
> RUN APPL /NAME $A2, OUT $GDSX.#LINE1.DEV2, NOWAIT/
When the LINE is started in SCF, GDSX references the access name for the LINE and
opens $IOP1. All devices on the LINE are then available for access. When requester
$A1 runs, GDSX opens SU $DEV1 under LINE1, establishing a thread from $A1
through $GDSX to $IOP1.#DEV1. When requester $A2 runs, GDSX opens SU $DEV2
under LINE1, establishing a thread from $A2 through $GDSX to $IOP1.#DEV2.
The last example can also be configured using ACCESSNAME attributes to specify the
files to be accessed through GDSX:
> PARAM MAXLINES 1
> RUN GDSE /NAME $GDSX, NOWAIT/
-> SCF
-> ADD LINE $GDSX.#LINE1, ACCESSNAME $IOP1
-> ADD SU $GDSX.#LINE1.D1, ACCESSNAME $IOP1.#DEV1
-> ADD SU $GDSX.#LINE1.D2, ACCESSNAME $IOP1.#DEV2
-> START LINE $GDSX.#LINE1
Note. SUs may not be added under a LINE unless the LINE is stopped. After starting a LINE,
if you want to add an SU under the LINE, you need to stop the LINE first.