Guardian Procedure Calls Reference Manual

function
input
INT:value
is an integer value specifying what change is to be made:
changes the poll state bit. In this case, function also specifies the relative address of the particular
station address within the address list (0 indicates the first entry, 1 the second entry, and so forth). The
parameter value, described below, specifies whether you want the bit to be set or cleared.
>= 0
changes the polling type. The parameter value described below specifies whether you want continuous
polling or you want the polling list to be traversed a finite number of times.
-1
restores all partially disabled stations.-2
parameter
input
INT:value
is an integer value used with the function value to specify what change is to be made.
The parameter value specifies whether you want the poll or select state bit set or cleared as follows:>= 0
Cleared0
Set1
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.
The parameter value specifies the desired type of polling as follows:0
Continuous polling0
Noncontinuous polling (traverse the polling list the specified number of times and then cease
polling).
> 0
The parameter value has no meaning. The CHANGELIST procedure, however, expects to be passed
three values; you must therefore supply a dummy parameter value.
1
Condition Code Settings
indicates that an error occurred (call FILE_GETINFO_ or FILEINFO).< (CCL)
indicates that the CHANGELIST procedure executed successfully.= (CCE)
does not return from CHANGELIST.> (CCG)
Example
In the following example, within a supervisor station, the 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.
CALL CHANGELIST ( FNUM , -1 , 10 );
Related Programming Manuals
For programming information about the CHANGELIST procedure, see the data communication
manuals.
CHANGELIST Procedure 119