Hoyles Electronic Developments have launched ZONEGUARD, a BS EN50131 Grade 3 zone omit unit.
The product fits between intruder detection devices and a control panel to allow devices to be omitted and re-instated without generating false alarms, the manufacturers report. Grade 3 detection devices such as passive infra red detectors must be fitted with independent alarm, anti-masking and anti-tamper facilities, the firm reports. The product design allows the various ‘end of line’ resistors for each condition to be passed through to the control unimpeded. In this way the resistor values are monitored and processed directly by the control panel, the makers say. Any value of alarm resistor greater than 1k can be used. The product can also be retro-fitted to conventional systems without anti-mask or to older four-wire systems, it is claimed. Seven modes can be configured on installation. In its simplest mode the product uses its integral keyswitch to omit or reinstate up to two detection zones. Other modes use the integral keypad or external devices such as a biometric reader or a combination of keyswitch and keypad.
