Availability Guide for Change Management

Making Application Subsystem Changes Online
Availability Guide for Change Management–125506
4-27
The Pathway Environment
RSC
The RSC product enables PC, Macintosh, or workstation applications to access Pathway
servers and other Tandem NonStop servers on the Tandem host system. RSC resides in
both the client and server environments. The workstation is the client; the Tandem host
system, with its Pathway transaction-processing software, is the server. The client
environment contains the client program, which includes RSC procedure calls, and
communications subsystems that handle the tasks involved in sending requests and
receiving replies. Communications subsystems support asynchronous, X.25, TCP/IP,
NetBIOS, and IPX/SPX links.
The primary RSC component in the server environment is the Transaction Delivery
Process (TDP), a multithreaded gateway process that handles message routing within the
Pathway environment in conjunction with the Pathsend API or the Pathway/TS terminal
control process (TCP). The TDP communicates with the workstation through the RSC
communications subsystem (RSC CSS) on the workstation. The TDP translates RSC
procedure calls from the client program into the same interprocess communication (IPC)
message format used between Pathway requesters and servers in the NonStop system
environment.
Pathsend
The Pathsend API is a set of procedure calls for communicating with servers on a
Tandem NonStop system. Applications residing on a remote system can access Pathway
servers on a Tandem NonStop system by communicating with Pathsend requesters.
Pathsend requesters can also access NonStop TUXEDO servers.
GDSX Facility
The Extended General Device Support (GDSX) communications subsystem product
simplifies the development of “front-end” processes and “back-end” processes for
communication with I/O devices. These devices can be of any type, including
workstations, terminals, ATMs, point-of-sale (POS) devices, and industrial robots.
Pathway/TS
Pathway/TS is a product that supports the client/server model for terminal-based
applications. Pathway/TS consists of the following components:
•
SCREEN COBOL compiler—The procedural language compiler used by
application programmers to develop SCREEN COBOL requester programs.
•
SCREEN COBOL Utility Program (SCUP)— The utility program used by
SCREEN COBOL programmers to access and manage the screen program object
libraries.
•
Terminal Control Process (TCP)—The process that interprets and executes
SCREEN COBOL requester programs and controls the I/O devices and processes on
which the transaction-processing applications run. These functions are performed
by a LINKMON process if the requester program is written in C, COBOL85, Pascal,
pTAL, or TAL.