User`s guide

DC 900-1339H 117
Appendix
C
Error Codes
There are several methods used by the DLI and FMP software to report errors
(Table C–1 lists the FMP errors).
1. The error code can be returned directly by the DLI function call. Typical errors
are those described in the Freeway Data Link Interface Reference Guide.
2. The FMP errors listed in Table C–1 can be returned in the global variable
iICPStatus. The DLI constants are defined in the file dlicperr.h.
3. The FMP errors listed in Table C–1 can also be returned in the
dlRead
pOptArgs.iICPStatus field of the response to a dlWrite request. The DLI sets the
dlRead pOptArgs.usProtCommand field to the same value as the dlWrite request
that caused the error. An example of this type of error is the
DLI_ICP_ERR_BAD_MODE invalid mode error.
4. The FMP error can be reported in an error report response to a
dlRead request.
The returned
dlRead pOptArgs.usProtCommand field is set to
DLI_PROT_RESP_ERROR, and the dlRead pOptArgs.iICPStatus field is set to the
actual error code. An example of this type of error is the
DLI_ICP_ERR_DSR_DOWN
error.
5. The FMP errors can also be returned in the error code byte within the 5-byte
header in data blocks that contain a 5-byte header (see Section 4.13.4 on page 87
and Section 4.13.5 on page 88). The error code values are listed in the “5-byte
Header Code” column of Table C–1.