I'd like to know, if possible, what's the time delay for "CF_LAST". Or is the price reported real time?
There are no field level delays on the datafeed, only RIC level delays. If you use real-time RIC (e.g. TRI.N), and you're entitled to view real-time data from this exchange, the price returned into CF_LAST will be the latest trade price from the real-time datafeed. If you're using a delayed RIC (e.g. /TRI.N) explicitly (you typed it in) or implicitly (you typed in TRI.N, but you're not entitled to real-time data from the exchange, so instead of TRI.N you get data from /TRI.N), then the delay time varies by exchange. Exchanges define after what delay time their market data is not fee liable, and some exchanges do not provide non fee liable delayed data at all. For US exchanges the delay time is 15 minutes.