In most modern locomotives, an “alerter” is used. This system, based on vigilance control works by alerting the motorman or engineer with a buzz or bell every few minutes or so. If he or she does not push a button on the driver’s console, the “alerter” system will automatically put the train into a full emergency brake application. To acknowledge the alert and thus prevent penalty brake application, the engineer or motorman reaches down to press the button and reset the system. Most major railroads in the United States and abroad use this system both in their freight and passenger operations. It is also used on the R143 and other New York City Subway cars while under CBTC operation. Older locomotives produced before 1995 do not carry this feature, but given the modular nature of the system it is not uncommon to find them retrofitted.
Thanks for the info. Now I do not have to worry about learning anything else today! :-)