The hot swap controller is designed to measure the current by sensing the voltage drop across a sense resistor. This resistor will have a very low ohmic value and will be in the main power path. Since the controller responds to the voltage drop across the sense resistor, the value of the sense resistor will determine the current limit as calculated by Rsense = Vsense / Imax. Additionally, the maximum power also needs to be calculated to ensure the correct power rating is selected. Also, the accuracy of the sense resistor can be a significant factor. However, high accuracy sense resistors are often more expensive and usually come in a specific range of values which may not be exactly suitable for the application. In this case, a combination of sense resistors can be used in parallel or series to obtain a desired value.