| Cogent C API and Utilities : Version 6.4 | ||
|---|---|---|
 | Cascade DataHub Functions |  |
| Cogent C API and Utilities : Version 6.4 | ||
|---|---|---|
| | Cascade DataHub Functions | |
DH_ReadPoint, DH_ReadExistingPoint — read a point from the Cascade DataHub.
#include <cogent.h>
ST_STATUS DH_ReadPoint(IP_hTASK myself, PT_pCPOINT ppoint, IP_hMSG hmsg, ER_hLIST elist );
ST_STATUS DH_ReadExistingPoint(IP_hTASK myself, PT_pCPOINT ppoint, IP_hMSG hmsg, ER_hLIST elist );
The task handle associated with this task. This should always be the return value from IP_NserveInit.
A pointer to a Cascade DataHub point structure, which must contain at least name. All other fields in the point structure should be 0 if this is the first call on this point, because they will be filled in by this call. Subsequent calls on the same point do not require zeroing any fields. If one point structure is used with several point names, the address field must be zeroed each time a different name is used in a call to this function.
A handle to a previously allocated message structure (using IP_MsgCreate) providing enough buffer space to handle the inter-process communication associated with the DataHub transaction.
Process communication associated with the DataHub transaction.
A return value containing error information. This is unimplemented in this version, and should be NULL.
This function reads a point from the DataHub. If the named point does not exist then DH_ReadPoint will create it on the DataHub with a confidence factor of zero and DH_ReadExistingPoint will return the error ST_NO_POINT.
| |  | |
| DH_PointAdd, DH_PointDivide, DH_PointMultiply |  | DH_RegisterAllPoints |
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