Type II error from a fixed decision threshold

A detector reads a value $X$. When there is no signal ($H_0$), $X \sim \text{Normal}(\text{mean } 0,\ \text{sd } 1)$. When a signal is present ($H_1$), $X \sim \text{Normal}(\text{mean } 3,\ \text{sd } 1)$. The decision rule is: declare "signal" whenever $X > 2$.

What is the probability this rule makes a type II error (fails to declare a signal when one is truly present)?