Abstract: Disclosed is a data communication method using a plurality of communication lines. In the method, a larger number of communication lines than the number of communication lines to be actually used for communication are connected, then other communication lines are disconnected when the number of communication lines to be actually used for communication are secured, and data are transmitted in parallel by means of the communication lines secured.

Abstract: An abnormality-handling instructing apparatus for use in a facsimile machine where the operator is able to be properly noticed an abnormality so that an appropriate handling can be effected to the abnormality. The apparatus comprises memory for storing abnormality codes and remedies for the abnormalities; an abnormality code generator for generating an abnormality code in accordance with an abnormality; and abnormality-handling instructing device for reading out the data from the memory in accordance with occurred abnormality and for outputting remedy in characters on the basis of the data.

Abstract: A data communication method in which a transmitting station divides data into a plurality of data blocks and transmits the data blocks in parallel through a plurality of communication lines, and a receiving station receives the data blocks transmitted from the transmitting station through the plurality of communication lines and composes the data blocks into original data. In the data communication method, it is detected that a new transmission request is present during a parallel data transmission through a plurality of communication lines, one or more of the communication lines are released to continuously use the remaining communication lines for the parallel data transmission in response to the detected new transmission request, and a new data transmission is performed through the released communication line or lines.