tdif or pdif?

Not sure which is better to use: tdif or pdif under the following scenario:

Trigger expression checks if in the last 20 minutes, the back price has remained the same. Say the back price is 2.02 and 20 minutes later it still needs to be 2.02 for the trigger to place a bet. I currently use: Selection's Trigger Expression pdif_20 is equal to 0.

Hi
pdif_ and tdif_ are similar, the difference being one measures price difference over time, and the other tick difference over time, both are dependent on market history depth.

if you are monitoring a lot of markets, it may be better to remember the selection prices, and 20 mins later compare against the remembered values. This will save the market history depth eating memory.

second trigger block in this example shows the basics.