System and method for automatically synchronizing multiple I/O devices with homogeneous and/or heterogeneous timing and I/O channel types. A graphical program specifying configuration and operation of a plurality of timed circuits, e.g., input circuits and/or output circuits, comprised on one or more I/O devices, may be created in response to user input, and executed to perform an I/O operation using the devices, where executing the program includes invoking software to: analyze the timed circuits to determine timing and triggering information for operation of the circuits, configure the circuits in accordance with the timing and triggering information, and operate the configured circuits to perform the operation. The analyzing may include determining the timed circuits, and one or more of: number, types, sharing, sources, exporting, and routing, of timing signals for each circuit, and starting/stopping orders for the circuits. User input may be received specifying setting and querying properties of the circuits.