GDSX Manual

Overview of GDSX
Extended General Device Support (GDSX) Manual–134303
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Indirect Terminal Access
This type of direct interface between DEVICE^HANDLER tasks and I/O processes
requires the terminal to have a unique Guardian file name that can be opened directly by
TSCODE. Some access methods that support this kind of direct access by Pathway/TS
are AM3270, ASYNC TERMPROCESS, X25AM, and CSS ASYNC (6100). Each of
these access methods requires a two-part file name for the device, except ASYNC
TERMPROCESS, which requires a one-part file name.
The following are examples of applications that can be handled with this type of
environment:
•
Accepting or initiating connections in X25AM
•
A two-step read in AM3270
•
Control-sequence translation for a nonsupported terminal, for example, the VT100
Indirect Terminal Access
There are applications, however, that involve shared data communication facilities where
the line (or message switching process) has a Guardian file name, but the individual
devices on the line do not. Some data communication products that do not allow direct
addressing of terminals on line are:
•
CP6100 ADCCP/NRM
•
CP6100 Bisync Multipoint
•
Envoy
•
EnvoyACP/XF
GDSX applications using these products cannot use a direct interface of
DEVICE^HANDLER tasks with I/O processes—LINE^HANDLER tasks must also be
used to implement communication protocols and to manage the line so that different
threads accessing the line do not interfere with each other.
When an application using Pathway/TS and GDSX is started, the GDSX process is run
first. For example, the following commands can be issued to run a GDSX object named
$GDS:
> PARAM MAXLINES 1
> RUN GDSE /NAME $GDS, NOWAIT/
The MAXLINES configuration parameter there is to be a maximum of one line in the
configuration.
Then SCF is 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 $GDS.#LINE1, ACCESSNAME $IOP1
-> ADD SU $GDS.#LINE1.DEV1
-> ADD SU $GDS.#LINE1.DEV2
-> ADD SU $GDS.#LINE1.DEV3
-> START LINE $GDS.#LINE1