Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CHANGELIST Procedure
parameter input
INT:value
is an integer value used with the
function value to specify what change is to be
made.
>= 0 The
parameter value specifies whether you want the poll or select state
bit set or cleared as follows:
0 Cleared
1Set
The meaning of this bit is somewhat different depending upon whether the
station list is that of a supervisor or a tributary station:
•
Within a supervisor station, the poll state bit enables (clears) or
disables (sets) the polling of the particular tributary station.
•
Within a tributary station, the poll state bit activates (clears) or
deactivates (sets) the tributary station with regard to its ability to
respond to a poll or select the designated station address.
= -1 The
parameter value specifies the desired type of polling as follows:
0 Continuous polling
> 0 Noncontinuous polling (traverse the polling list the specified number of
times and then cease polling).
= -2 The
parameter value has no meaning. The CHANGELIST procedure,
however, expects to be passed three values; you must therefore supply a
dummy
parameter value.
Condition Code Settings
< (CCL) indicates that an error occurred (call FILE_GETINFO_ or FILEINFO).
= (CCE) indicates that the CHANGELIST procedure executed successfully.
> (CCG) does not return from CHANGELIST.
Examples
CALL CHANGELIST ( FNUM , -1 , 10 );
In this example, within a supervisor station, this call enables limited polling in which the
station list is traversed 10 times. Polling does not begin, however, until READ is
subsequently called. After the tenth pass through the polling list, polling ceases.
Related Programming Manuals
For programming information about the CHANGELIST procedure, refer to the data
communication manuals.