No dll. Only indicator. There are two indicators:
1. HISTORYDATA-MTP.mq4 - This exports time-frame as per the available time-frame from MT4. You have options to put True or False for all the time-frames available.
2. Convert_Timeeframe.mq4 - Use this if you want your own time-frame not available in MT4. There is a multiplier which you have to enter. For example, if you want 3 mins time frame, open 1 min chart on MT4 and insert this indicator on the chart and select 3 as the multiplier.
(The second indicator is based on Period_Converter_Opt from metaquotes.net forum. I have modified it and made changes as the original one does not release the csv file and locks it to be read by other instruments)
There is update frequency available. Zero means real time. The csv file gets saved in ..experts/files folder.
Is it similar to MT4 to AMIBROKER plug in?it too has one indicator,rateserver,somedlls.?can you share your indicator alongwith short write up?