Envoy Application Programming Manual

File-System Procedures
Envoy Application Programming Manual—427159-001
C-9
CHANGELIST
If the function value is -1, then the parameter value specifies the desired type of
polling, as follows:
If the function value is -2, then the parameter value has no meaning. The CHANGELIST
procedure, however, expects to be passed three values and you must therefore supply a
dummy parameter value.
Condition Codes
Examples
CALL CHANGELIST (fnum,7,2);
In a supervisor station, this call disables polling or selection (whichever applies) for the
eighth station entry in the address list.
CALL CHANGELIST (fnum,4,0);
In a supervisor station, this call enables polling or selection (whichever applies) for the
fifth station entry in the address list.
CALL CHANGELIST (fnum,0,2);
In a tributary station, this call deactivates the port associated with the first entry in the
address list.
CALL CHANGELIST (fnum,-1,0);
In a supervisor station, this call enables continuous polling. The polling process does not
begin, however, until a READ call is subsequently issued.
CALL CHANGELIST (fnum,-1,10);
In a supervisor station, this call enables a polling cycle whereby the polling portion of
the address list is traversed ten times. The polling cycle does not begin, however, until a
READ call is subsequently issued. After the tenth pass through the poll list, the polling
cycle ceases.
CALL CHANGELIST (fnum,-2,0);
In a supervisor station, this call reenables the polling of all partially disabled (previously
nonresponding) stations.
0 = Continuous polling.
c>0 = Noncontinuous polling (traverse the poll list the specified number of
times and then cease polling).
< (CCL) Indicates that an error occurred (call FILEINFO).
= (CCE) Indicates that the CHANGELIST procedure was executed successfully.