dpGetAsynch()
Reads values of data point attributes at a particular source time and writes them to variables.
Synopsis
int dpGetAsynch(time t, string|dyn_string dp1, <type1>|<dyn_type1> &var1 [, string|dyn_string dp2, <type2>|<dyn_type2> &var2 ...]);
Parameter
Parameter | Meaning |
---|---|
t | source time |
dp1, dp2, ... | data point attributes to be read
Anmerkung: Please note that in the dpGetAsynch
function, the parameter dp (data point) cannot be a dyn element,
but each data point that you want to query must be specified
separately.
|
var1, var2, ... | variables to be written |
Return Value
If the function was successfully executed, it returns 0 and in the event of a failure -1. The return value 0 only indicates that the message was correctly sent to Event Manager.
Errors
Independently of the return value, errors can be retrieved with getLastError() (nonexistent data points, missing arguments or no read permission).
Description
The function dpGetAsynch() reads the values of the data point attributes dp1, dp2, ... with the source time t from the database and writes them to the variables var1, var2, ... of the appropriate type.
If an alias is used for a query, this is passed as a parameter to the external query function; function calls for dpQuery() and alertGetPeriod().
With the help of dpGetAsynch() only attributes of the configs "_original", "_online", "_offline" and "_corr" can be retrieved. See also dpGetPeriod(). You can find information on querying whether the values of the required attribute are located in the database. The parameter t1 may not predate 1.1.1970 0:0 (UTC).
If a definition for a config or attribute does not exist, the following defaults are used:
Function | Default |
---|---|
dpSet*() | _original.._value |
dpGet() | _online.._value |
dpGetAsynch() | _offline.._value |
dpGetPeriod() | _offline.._value |
dpConnect() | _online.._value |
dpDisconnect() | _online.._value |
Assignment of the valve regulation ratio from March the 5th, 12.30 to the variable x
main()
{
dpGetAsynch(makeTime(1996, 3, 5, 12, 30), "Valve17.opening:_offline.._value", x);
}
Assignment
Data point function, waiting Control function
Availability
CTRL