P.528 supports the following list of return codes.
| Value | Const Name | Description |
|---|---|---|
| 0 | SUCCESS |
Successful execution |
| 1 | ERROR_VALIDATION__D_KM |
Path distance must be >= 0 km |
| 2 | ERROR_VALIDATION__H_1 |
Low terminal height must be >= 1.5 meters |
| 3 | ERROR_VALIDATION__H_2 |
High terminal height must be >= 1.5 meters |
| 4 | ERROR_VALIDATION__TERM_GEO |
Low terminal must be <= high terminal height |
| 5 | ERROR_VALIDATION__F_MHZ_LOW |
Frequency must be >= 100 MHz |
| 6 | ERROR_VALIDATION__F_MHZ_HIGH |
Frequency must be <= 30 000 MHz |
| 7 | ERROR_VALIDATION__PERCENT_LOW |
Time percentage must be >= 1 |
| 8 | ERROR_VALIDATION__PERCENT_HIGH |
Time percentage must be <= 99 |
| 10 | ERROR_HEIGHT_AND_DISTANCE |
Terminals are occupying the same point in space (they are the same height and 0 km apart) |
In addition to return codes, P.528 supports return warning flags to the caller. Warning flags are bitwise set, allowing the P.528 model to return multiple warnings for a single function call. Warning flags only need to be parsed if a return code of SUCCESS_WITH_WARNINGS is returned by a function call.
| Value | Const Name | Description |
|---|---|---|
| 0x00 | NO_WARNINGS |
No warning flags |
| 0x01 | WARNING__DFRAC_TROPO_REGION |
Warning that the diffraction and troposcatter model may not be physically consistent with each other. Caution should be taken when using the result |
| 0x02 | WARNING__HEIGHT_LIMIT_H_1 |
Terminal 1 height above limit defined within in-force Recommendation text. Results should not be intepreted as an official prediction of Recommendation ITU-R P.528, but instead treated as informative |
| 0x04 | WARNING__HEIGHT_LIMIT_H_2 |
Terminal 2 height above limit defined within in-force Recommendation text. Results should not be intepreted as an official prediction of Recommendation ITU-R P.528, but instead treated as informative |