Hi, i am a newbye of pipeline scripting language, i'd like to write a protocol able to read generic sd file, get properties name from such sd file and perform some calculation. the first component i used was an sd reader where i kept some selected properties, then i used a keep component in order to create a propertylist. In a custom manipulator component in the initial expression tab i wrote:
@name:='';
for #i in 1 .. numproperties()
loop
if (ithpropertyname(#i) rlike '^LOGP') then
@name:=ithpropertyname(#i);
end if;
end loop;

but i got the follwing error message:

numproperties: No property list is available.

Why in the pipeline the property list is unavailable? what am i doing wrong? could you please send me an example?
regards,
Pasquale