Exchange/SNA Manual

Operational Considerations
Using the Exchange/SNA Command Interpreter
104700 Tandem Computers Incorporated 2–3
Operational
Considerations
There are a number of operational considerations you need to be aware of when using
the Exchange/SNA command interpreter. These considerations are discussed below.
Nowait Operation The Exchange/SNA command interpreter performs send and receive operations as
nowait I/O. When you execute a SEND or RECEIVE command, you see the command
interpreter’s prompt as soon as the send or receive operation has started. You do not
have to wait for the operation to complete before entering another Exchange/SNA
command.
You cannot disconnect from the line server (without aborting the send or receive
operation) while a send or receive operation is in progress. You can, however, initiate
another send or receive operation using another subdevice supported by the line
server. You can have up to six concurrent send and receive operations (provided no
one else is using the line server).
You can use the SHOW command to determine if a send or receive operation is in
progress. When a send or receive operation is completed, the command interpreter
displays a message that shows the number of records transferred.
The BREAK Key If you press the BREAK key while using the Exchange/SNA command interpreter,
control of your terminal is passed back to the command interpreter, which is usually
TACL. You can then enter commands, run other programs, and perform any
operations that you can normally perform from TACL.
To return to the Exchange/SNA command interpreter, enter the TACL PAUSE
command. The PAUSE command returns control of your terminal to the
Exchange/SNA command interpreter. For more information about the PAUSE
command, see the TACL Reference Manual.
Using Command Files Instead of entering commands interactively at the Exchange/SNA command
interpreter’s prompt, you can enter a sequence of commands in an EDIT-format file
and have the command interpreter read and execute the commands in that file. Such a
file of Exchange/SNA commands is called a command (OBEY) file.
To perform a given operation, the same sequence of commands is used whether you
are entering the commands interactively or using a command file. The same rules
govern the use of the command interpreter and the allowed sequence of operations.
You can instruct the Exchange/SNA command interpreter to read and execute a
command file two ways:
You can use the IN option in the RJECIS command, which is the command to start
the Exchange/SNA command interpreter.
You can use the OBEY command.
Each of these ways is discussed below.