In some embodiments, a controller is configured to be operably coupled to a series of safety relays. Each safety relay is coupled to a machine from a plurality of machines. The controller is configured to receive a signal indicative of a potential collision between any machine from the plurality of machines that is coupled to the at least one of the safety relays that was activated. The controller is configured to send, in response to the signal indicative of the potential collision, a signal to at least one of the safety relays from the series of safety relays to activate the at least one of the safety relays, thereby stopping motion of any machine from the plurality of machines that is coupled to the at least one of the safety relays that was activated.