ABB Triguard SC300E User Manual

Contents

ABB Triguard SC300E User Manual Manual pdf 8 page image

8 MDO16GNS October 2005 – Issue 2Triguard SC300EFigure 2 - 3 Field output connector J2 pinoutsConnector J3 pin 1c is connected to earth.All other pins on J3 are connected to field supply return.THEORY OF OPERATIONThe channel output command information from the main processor follows three identical pathsthrough the MDO16GNS (see Figure 2- 4 ), each path is controlled by its own microcontroller inthe common interface. In order to minimise the number of data connections across the 1kVsystem - to -field barrier, the channel data are converted to serial form before entering the modulefrom the common interface. In this manner 16 output channels can be served by just threepaths instead of 48.The three data streams are each applied to opto- isolators which mark the interface betweenthe system and field sides of the circuit and provide a system- to -field channel isolation of 1kV.