The present invention comprises methods and apparatuses that can provide reliable communications between a computer and a haptic interface device. The methods and apparatuses can provide communication that is more secure against errors, failures, or tampering than previous approaches. Haptic devices allow a user to communicate with computer applications using the user's sense of touch, for example by applying and sensing forces with the haptic device. The host computer must be able to communicate with the haptic device in a robust and safe manner. The present invention includes a novel method of accomplishing such communication; a computer-readable medium that, when applied to a computer, causes the computer to communicate according to such a method; and a computer system having a host computer and a haptic device communicating according to such a method.