The Error Traps, more commonly known in modern programming as error handling or exception handling, is the practice of anticipating, detecting, and responding to errors or exceptional conditions that may occur while a program is running. Instead of allowing an error to cause the program to crash abruptly, error trapping allows the programmer to define a specific course of action to handle the problem gracefully.
In the context of controlling a programmable power supply, many things can go wrong. For example, a command might be sent with an invalid argument (e.g., a voltage outside the supply's range), the communication cable could become disconnected, the instrument might not respond in time (a timeout), or the power supply itself could report an internal fault (like an over-temperature condition). A robust control program will implement error traps for these situations. This is often done using try...catch or try...except blocks in the code. The main control logic is placed in the try block. If an error occurs during its execution, the program immediately jumps to the corresponding catch or except block. This block contains the "error handler" code, which could log the error to a file, display a message to the operator, attempt to reset the instrument, or safely shut down the test sequence.
Effective error trapping is essential for creating reliable and safe automated test systems, as it prevents unexpected failures and provides mechanisms for recovery and diagnosis.