ViewPoint Manual
Introduction to ViewPoint
ViewPoint Manual—426801-001
1-8
Customizing ViewPoint
TACL Screen
If available, the TACL screen provides all the existing capabilities of TACL (see the 
TACL Programmer’s Guide) plus access to the Define Process library of commands.  
The TACL screen is part of ViewPoint, so you can use function keys on this screen to 
switch readily to other parts of the ViewPoint application. Conversely, you can easily 
switch back to TACL function, such as checking the availability of a file and running a 
program such as PERUSE to check on printer status.
Define Process Library
The Define Process library is a library of TACL commands available through 
ViewPoint. These commands permit the creation of multiple subsystem control 
processes throughout the network. Such control processes keep running as background 
processes, available for access by the operator without the normal delays associated with 
starting a remote process.  This essentially provides easy access to all available 
management utilities that exist in a system or network.
Define Process also enables you to create composite commands that direct commands to 
one or more subsystem control processes. This capability manages the communication 
between operators and defined background processes through queues. Commands to a 
process are queued in an input queue; responses from a process are queued in an output 
queue.
Figure 1-4 is a simplified illustration of how ViewPoint manages control and inquiry 
through the TACL screen.
Customizing ViewPoint
ViewPoint can be fully customized with features tailored for a particular site or system 
or even a particular terminal.
If your responsibility is to customize ViewPoint, you can use one of the following 
procedures:
Figure 1-4. Overview of Control and Inquiry
CDT004.cdd
Operator 
Terminal
Define
Commands
Process
TACL
Subsystem 
Processes
Subsystem
Interpreters
Command
Output Queue
Input Queue










