Abstract: A printer (2; 52) prints documents which, after arriving in a finishing system (1; 51), are detected and finished in an order corresponding with the order in which the documents have been printed by the printer (2; 52). The printer (2; 52) generates verification markings following one of the documents and prior to a next one of the documents. The number of documents that arrive in an interval limited by at least one of the verification markings are counted and compared with a reference number. An error message is generated if the counted number of arrived documents does not agree with the reference number. This makes it possible to monitor whether, after the documents have been printed, any faults have occurred. Further, a system for finishing documents is described.

Abstract: A system comprising a mail processing apparatus includes a number of processing stations such as for instance a printer and an inserter. In addition, the system comprises a control system which controls at least one processing station for assembling sheets to form at least one document to be mailed or for processing received documents. The system further comprises at least one external diagnostic device separate from the mail processing apparatus and a communication channel between the control system and the diagnostic device. The control system is arranged for performing diagnostic tests for detecting, for instance, malfunctions, deviations in performance and/or required preventive maintenance in a processing station. The diagnostic device initializes via the communication channel the performance of said tests and/or receives the results of the tests for further processing.