Abstract: A method for exchanging data using a controller includes selectively setting an exchange mode to one of a synchronous mode and an asynchronous mode, and determining whether to execute an input data exchange or an output data exchange. The input data exchange is based at least in part on an input reference that identifies an input/output (I/O) module from which the input data is retrieved, and the output data exchange is based at least in part on an output reference that identifies the I/O module to store the output data.

Abstract: A calf pulling device comprising an elongate rectangular shaft with a multiplicity of apertures formed therein along the length thereof, with a rotatable detachable breech spanner mounted on one end thereof, said shaft having a slidable jack mechanism mounted thereon, said jack mechanism including locking tongues and an operating handle and a chain hook whereby the jack mechanism can be progressively moved along said shaft by manipulation of said handle to steadily draw the calf from the cow and which can be quickly and instantaneously released from a rigid connection with the shaft to release the pressure on the calf whenever necessary to avoid injury thereto.