Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

Chapter 2 51
Controlling Asynchronous Devices Programmatically
MPE/iX System Intrinsics
If the condition code indicates that an error condition occurred during
execution of an intrinsic, you may want to obtain more specific
information about what took place. You can do so by calling FCHECK to
obtain details such as the error code associated with the problem that
occurred, and FERRMSG to display the message associated with that
error code. See the discussions of these intrinsics in the Intrinsics
Reference section of this manual.
Table 2-1 Condition Codes
Status Parameter
While many intrinsics return an error parameter, only MPE/iX native
mode intrinsics, such as the HPFOPEN intrinsic described in this
manual, use the status parameter in place of condition codes as their
error checking convention. The status parameter is a 32-bit signed
integer which returns error information in one 16-bit field and
subsystem information in its other 16-bit field.
The information returned by the status parameter is more explicit
than that available through condition codes. The intrinsics that use the
status parameter do not return meaningful condition code values.
The status parameter is optional, but it is strongly advised that you
use this feature whenever it is provided. If an error or warning
condition is encountered during execution of a native mode intrinsic
and you did not specify the status parameter, the intrinsic causes the
calling process to abort.
See the discussion of HPFOPEN in this manual, as well as the MPE/iX
Intrinsics Reference Manual for more information on using the status
parameter.
Abort Errors
The errors that return condition code or status information to your
program are generally recoverable and do not cause your program to
abort. Another type of error occurs if a calling program attempts to pass
Condition Code Value General Meaning
CCE (=) 2 Condition Code Equal. This generally
indicates that the request was granted.
CCG (>) 0 Condition Code Greater Than. A special
condition occurred but may not have affected
the execution of the request. (For example,the
request was executed, but default values were
assumed as intrinsic call parameters.)
CCL (<) 1 Condition Code Less Than. The request
was not granted, but the error condition may
be recoverable.