At first, DB was going to work together modern DMUs bought from different makers, but because of software trouble, this proved to be impossible. Therefore the "Class 642" can only be mechanically coupled with other DMUs like the "Class 643".
æ t WORD_BOUNDARY f ɜː s t WORD_BOUNDARY d iː b iː WORD_BOUNDARY w ʌ z WORD_BOUNDARY ɡ oʊ ɪ ŋ WORD_BOUNDARY t ə WORD_BOUNDARY w ɜː k WORD_BOUNDARY t ə ɡ ɛ ð ə ɹ WORD_BOUNDARY m ɑ d ə ɹ n WORD_BOUNDARY d iː ɛ m j uː z WORD_BOUNDARY b ɔ t WORD_BOUNDARY f ɹ ʌ m WORD_BOUNDARY d ɪ f ɹ ə n t WORD_BOUNDARY m eɪ k ə ɹ z WORD_BOUNDARY b ʌ t WORD_BOUNDARY b ɪ k ʌ z WORD_BOUNDARY ʌ v WORD_BOUNDARY s ɔ f t w ɛ ɹ WORD_BOUNDARY t ɹ ʌ b ə l WORD_BOUNDARY ð ɪ s WORD_BOUNDARY p ɹ uː v d WORD_BOUNDARY t ə b i WORD_BOUNDARY ɪ m p ɑ s ɪ b ə l WORD_BOUNDARY ð ɛ ɹ f ɔ ɹ WORD_BOUNDARY ð ə WORD_BOUNDARY k l æ s WORD_BOUNDARY s ɪ k s h ʌ n d ɹ ɪ d WORD_BOUNDARY f ɔ ɹ t i WORD_BOUNDARY t uː WORD_BOUNDARY k æ n WORD_BOUNDARY oʊ n l i WORD_BOUNDARY b iː WORD_BOUNDARY m ɪ k æ n ɪ k l i WORD_BOUNDARY k ʌ p ə l d WORD_BOUNDARY w ɪ ð WORD_BOUNDARY ʌ ð ə ɹ WORD_BOUNDARY d iː ɛ m j uː z WORD_BOUNDARY l aɪ k WORD_BOUNDARY ð ə WORD_BOUNDARY k l æ s WORD_BOUNDARY s ɪ k s h ʌ n d ɹ ɪ d WORD_BOUNDARY f ɔ ɹ t i WORD_BOUNDARY θ ɹ iː WORD_BOUNDARY