Test box for function check of power block of SINAMICS/MM4PX Frequency converter power unit To be able to use the test box, the measuring line set 6AG1064-1AO05-0AA0 is required. Successor/substitution: Current Transformer Test Box= 9LD1610-0AA01 DC Link Test Box= 9LD1610-0AA02 Converter Test Box= 9LD1610-0AA03