Description

The PT971 Intrinsically Safe Single Channel Protocol Translator is a single channel protocol translator for the 970 series analogue addressable intrinsic safe sensors. It must be used with the GBX70 barrier.

Application

To enable the use of standard control (NON IS) fire panels in intrinsically safe systems, a device to “translate” voltage levels from the loop to levels compatible with the I.S. requirements is required. The PT971 also “boosts” the current pulses returned by the I.S. detectors.

The PT971 Intrinsically Safe Single Channel Protocol Translator is a loop-powered device that draws a low quiescent current and is therefore transparent to both the loop driver and the I.S. detectors.

Construction

The translator is housed in a moulded plastic enclosure that can be either clipped onto a standard 35mm DIN rail (DIN 46277) or panel mounted by using pull-out latches in the base. The PT971 should only be connected to a single intrinsically safe circuit through an appropriate safety barrier. Each channel is thus capable of supplying up to twenty 970 series I.S. devices.