| 摘要 |
PURPOSE:To simplify the structure of a control program and to shorten the processing time of the character processing and etc., by determining character classification codes indicating statuses of MODEMs and network controllers and providing a monitor part which detects the change of statuses. CONSTITUTION:In case of the character reception processing or the like of a certain line, contents of an MODEM status register MDS are compared with contents of the register MDS, which are stored in an MODEM status memory MDS1 in the just preceding scanning cycle, in exclusive OR circuits EOR1- EORn, and corresponding EORs output ''1'' when they do not coincide with each other. An MODEM status encoder MEC outputs a character classification code indicating the status of the MODEM corresponding to bits ''1'' and outputs this code to a character table buffer CTB. Meanwhile, a character classification code is outputted from a sense buffer encoder SEC in accordance with respective bits of a sense buffer SSB and is stored in the buffer CTB. When a change is detected in contents of the register MDS, a gate A3 is closed by the output of the encoder MEC to stop the output of the encoder DEC, thus detecting the abnor mal state of the MODEM. |
