This article explains the step by step process of identifying and resolving code errors as well as the steps in testing and optimizing of the Expert Advisor input parameters. You will learn how to use Strategy Tester of MetaTrader 5 client terminal to find the best symbol and set of input parameters for your Expert Advisor.
A monitoring of the current state of a trade account implies controlling open positions and orders. Before a trade signal becomes a deal, it should be sent from the client terminal as a request to the trade server, where it will be placed in the order queue awaiting to be processed. Accepting of a request by the trade server, deleting it as it expires or conducting a deal on its basis - all those actions are followed by trade events; and the trade server informs the terminal about them.
Creating a robust trading robot cannot be done without an understanding of the mechanisms of the MetaTrader 5 trading system. The client terminal receives the information about the positions, orders, and deals from the trading server. To handle this data properly using the MQL5, it's necessary to have a good understanding of the interaction between the MQL5-program and the client terminal.