Guard Patrolling Systems
A guard tour patrol system is a system for logging the rounds of employees in a variety of situations such as security guards patrolling property, technicians monitoring climate-controlled environments. It helps ensure that the employee makes his or her appointed rounds at the correct intervals and can offer a proof of record for legal reasons. Such systems have existed for many years using mechanical watchclock-based systems (watchman clocks/guard tour clocks/patrol clocks). Computerized systems were first introduced in Europe in the early 1980s. Modern systems are based on handheld data loggers and RFID readers.
The system provides a means to record the time when the employee reaches certain points on their tour. Checkpoints or watchstations are commonly placed at the extreme ends of the tour route and at critical points such as vaults, specimen refrigerators, vital equipment, and access points. Some systems are set so that the interval between stations is timed so if the employee fails to reach each point within a set time, other staff are dispatched to ensure the employee's well-being.
An example of a modern set-up might work as follows: The employee carries a portable electronic sensor (PES) or electronic data collector which is activated at each checkpoint. Checkpoints can consist of iButton semiconductors, magnetic strips, proximity microchips such as RFIDs, or optical barcodes. The data collector stores the serial number of the checkpoint with the date and time. Later, the information is downloaded from the collector into a computer where the checkpoint's serial number will have an assigned location (i.e. North Perimeter Fence, Cell Number 1, etc.). Data collectors can also be programmed to ignore duplicate checkpoint activations that occur sequentially or within a certain time period. Computer software used to compile the data from the collector can print out summaries that pinpoint missed checkpoints or patrols without the operator having to review all the data collected. Because devices can be subject to misuse, some have built-in microwave, g-force, and voltage detection.
In the analog age, the device used for this purpose was the watchclock. Watchclocks often had a paper or light cardboard disk placed inside for each 24-hour period. The user would carry the clock to each checkpoint, where a numbered key could be found (typically chained in place). The key would be inserted into the clock where it would imprint the disk. At the end of the shift or 24-hour period an authorized person (usually a supervisor) would unlock the watchclock and retrieve the disk.