PNL or PNL Underlying

I want to exit the trade if PNL for current set is < -2500 (loss of -2500).

The condition that I have mentioned under Exit is
–> tt_PNL_Underlying ( ‘strategy_id’, ‘run_counter’, ‘NIFTY BANK’ ) < tt_Number ( ‘-2500’ )

I hope Exit is the right place to code it.And also the condition is coded correctly.

I have coded above on the basis of What is difference between PNL and PNL underlying?. But I am missing some good documentation. Is there any documentation that I can refer to?