Although Owen made brief visits to the United States, London became his permanent home and the centre of his activities in 1828. After an extended period of friction with William Allen and some of his other business partners, Owen relinquished all of connections to New Lanark. He is often quoted as comment Allen at the time, "All the world is queer save thee and me, and even thou art a little queer". Having invested most of his personal fortune in the failed New Harmony communal experiment, Owen was no longer a wealthy capitalist; however, he remained the head of a vigorous propaganda effort to promote industrial equality, free education for children, and adequate living conditions in factory towns. In addition, he delivered lectures in Europe and published a weekly newspaper to gain support for his ideas.  In 1832 Owen opened the National Equitable Labour Exchange system, a time-based currency in which the exchange of goods was effected by means of labour notes; this system superseded the usual means of exchange and middlemen. The London exchange continued until 1833; a Birmingham branch operated for only a few months until July 1833. Owen also became involved in trade unionism. He briefly served as the leader of the Grand National Consolidated Trade Union (GNCTU) before its collapse in 1834.  Socialism first became current in British terminology in the discussions of the Association of all Classes of all Nations, which Owen formed in 1835 and served as its initial leader. Owen's secular views also gained enough influence among the working classes to cause the Westminster Review to comment in 1839 that his principles were the actual creed of a great portion of them. However, by 1846, the only long-lasting result of Owen's agitation for social change, carried on through public meetings, pamphlets, periodicals, and occasional treatises, remained the co-operative movement, and for a time even that seemed to have utterly collapsed.

Answer this question "what did the exchange system do" by extracting the answer from the text above.
a time-based currency in which the exchange of goods was effected by means of labour notes;