To find out the meaning of any message id, just run the DSPMSGD command
Example: dspmsgd CPA5714

Returns :
Message ID . . . . . . . . . : CPA5714
Message file . . . . . . . . : QCPFMSG
Library . . . . . . . . . : QSYS

Message . . . . : System cannot call controller &24. No lines available. (C
R)
Cause . . . . . : When attempting to call out using controller &24, the
system was unable to connect controller &24 to a line description found in
the switched line list (SWTLINLST). The most common reason for this failure
is that none of the line descriptions in the switched line list is in the
proper state to call out.
Other possible reasons a line is not selected are:
— The maximum number of active controllers (MAXCTL parameter) for a line
description has been exceeded.
— There are no lines in the switched line list (SWTLINLST parameter) of the
controller description.
— A line description may be attached to the *INTERNAL port of a *BASE NWSD.
More…

To find out the meaning of any message id…

Maybe most often, to find additional information about a message, move the cursor to somewhere in the message and press <F1>. The <F1> key is the standard <Help> key.

All of the text that can be seen by displaying the message description can be seen by displaying the message help. In addition, substitution variables will have values to connect the message to the specific components that have the error.

Also, the program that sent the message and the program that the message was sent to can be see with the text. The sending and receiving instruction or statement numbers are included.

But maybe we need to find out why the question was asked. The question simply asks about a message identifier. There is no context.

If the message ID appeared somewhere, there should be message text in the same place. Why ask about it here? Messages are self-explanatory. If a programmer is asking, we should wonder what a programmer who doesn’t know about error messages is doing. A programmer can’t be very reliable in this environment without knowing about messages. If an operations person is asking, we might wonder the same as about a programmer. A consultant? A manager?

The point is that an attempted technical description might be precisely correct, yet have no value to the OP. A new programmer might see “(CPA5714)” in a CL MONMSG command and not know what the purpose of MONMSG is. Or it might be a literal in a RPG program where an API error code is being checked. An obvious question that might come out of that is to ask what the “CPA5714″ means.

The appropriate answer in those cases would include a short introduction to the exception basis of i5/OS and to message passing and handling. The actual message description, and even reference to DSPMSGD, won’t help. It is likely even to be more confusing.

So, why are you asking? Where did you see “CPA5714″? What problem are you trying to solve?

Tom