Function
Attaches a line of a multiplexer or uniplexer to a named conceptual, and causes the current job to be terminated as if a LOGOUT command had been given.
Format
Format 1 is used by the central operator to attach a line of a
multiplexer to a given conceptual.
Format 2 is used by the central operator to attach a line of a
uniplexer to a given conceptual.
Formats 3 and 4 are for use from a MOP terminal if the user wishes to
attach his teminal to a given conceptual. Format 3 should be used in NO
USER context; format 4 in USER context.<.P>
Forbidden contexts
Formats 1 and 2 - NOT OPERATOR, REMOTE
Format 3 - USER, OFF-LINE, BREAK-IN
Format 4 - NO USER, OFF-LINE, BREAK-IN
Execution
A check is made to see whether a suitable conceptual line is available:
if not, a command error is reported. If the conceptual has not already
been ONLINEd, the required
conceptual line is marked 'attached' in the Installation Description
File (IDF) and the ATTACH command waits for the ONLINE command to be issued. During this wait, the
ATTACH command can be abandoned in one of the following ways:
The action of the ATTACH command, either when the ONLINE command is issued or if the conceptual is already ONLINE, varies according to whether it was issued from an operator's console or from a MOP console.
Command issued from Operator's Console
If the attach command was issued by the operator, the connection is made
and the entry for the specified line in the IDF is marked to indicate
that it is now attached to a conceptual and must therefore not be used
by the system. Pointers are set up in the IDF to connect the line with
the specified conceptual and the conceptual line number for the line is
stored. When the ATTACH command has successfully terminated, one of the
following messages is output on the operator's console:
UNIT n LINE m ATTACHED TO LINE
p OF CONCEPTUAL z
if the line being attached is a multiplexor line, or
UNIT n ATTACHED TO LINE p OF
CONCEPTUAL z
if a uniplexor is being attached to the conceptual.
Command issued from MOP Console
If the ATTACH command was issued from a MOP console, various checks are made before the specified line is attached. In a NO USER context the user's password is requested and checked (except for LOW SECURITY users): if either the password or the user name is invalid, an error message is output and the command is abandoned. If the conceptual was set up with a user name, a check is made to ensure that the MOP user is allowed to attach to this conceptual (that is, has a READ trap) and, if not, an error message is output and the command is abandoned.
Following these checks, the attachment is made in the same way as for an
ATTACH command issued from the operator's console, and the following
message is output to the MOP console:
YOU ARE ATTACHED TO LINE p OF CONCEPTUAL
z
Examples
ATTACH U29.L13,CL FRED.L2
ATTACH U7,CL FRED.L5(3)
ATTACH :BILL,CL FRED
Error Messages
z IS NOT A VALID LINE NUMBER
z IS NOT A VALID CONCEPTUAL NAME
UNIT z IS NOT A MULTIPLEXER OR UNIPLEXER
THIS CONCEPTUAL DOES NOT EXIST
NO LINES AVAILABLE ON THIS CONCEPTUAL
THIS LINE IS ALREADY ATTACHED
UNIT z IS BUSY
LINE z IS BUSY
THIS UNIT IS ALREADY ATTACHED
TOO MANY PARAMETERS
USER NAME/PASSWORD INVALID
z IS NOT A CORRECTLY FORMED NAME (RETAIN (local name))
z IS AN UNKNOWN MONITORING FILE CATEGORY
YOU ARE NOT ALLOWED TO THIS CONCEPTUAL
Cancels the attachment of the specified line of a multiplexer or a uniplexer to a conceptual.
Format
CANCEL ATTACH unit number,line number
The line number is only applicable to multiplexers and should not be used when referring to a uniplexor.
Forbidden contexts
None
Execution
If the specified line was attached by an ATTACH command issued by the central operator, the line will be detached from the conceptual named in the ATTACH command. When the CANCEL ATTACH command has been implemented, the line will return either to MOP or other system use, as appropriate.
Error Messages
LINE BUSY
LINE NOT ATTACHED
UNIT BUSY
UNIT NOT ATTACHED