This function retrieves values for points established with pisn_evmestablish. The events are in the same order that they were received by the pi System. This does not mean that the time stamps are in ascending order. On a PINet node, events are in the order that they were received by the PINet system. This means that events from a home node are mixed with events from the PINet node in an indeterminate manner. All points are disestablished if pisn_evmexceptions is not called for 30 minutes.

C format

int32 pisn_evmexceptions(

int32 PIPTR * count,

int32 PIPTR * pt,

float PIPTR * rval,

int32 PIPTR * istat,

int32 PIPTR *timedate );



System error




Count is < 1


No points established


Exception buffer overflowed


Server changed before exception buffer emptied. Buffered data lost


count (passed, returned)

Passed with the maximum number of events to return, and returned with the actual number of events if successful

pt (returned)

Array of point numbers corresponding to the returned events.

rval (returned)

Array of floating point values whose meaning depends on the point type

istat (returned)

Array of integer values for each point whose meaning depends on the point type

timedate (returned)

Array of time stamps

Usage Notes

This function and the extended function, pisn_evmexceptionsx, both draw points from the same queue on the PI Server.

PI 2 servers allow a program to sign up for exceptions for up to one-fourth the maximum number of points for the system. Also, the total number of points signed up for exceptions for all programs may be one half the maximum point count of the system.

PI 3 servers allow a maximum of 3000 pending events in the queue per consumer. This default may be changed by the PI system administrator.

Enabling Operational Intelligence