| 摘要 |
PURPOSE:To test easily the route of MODEM-line-MODEM, by giving a check data transmitting function and a check data receiving and collating function to the MODEM. CONSTITUTION:A transmitting part of a MODEM1 is provided with a check data generating part 21; and in case of the test, check data is transmitted repeatedly to a receiving part of a MODEM2 of the other party through a switch 23 and a modulating/demodulating part 9-1. Received check data is reproduced in a modulating/demodulating part 9-2 and is inputted to a comparator 25 through a switch 24. The comparator 25 compares data from a check data generating part 22, which generates the same data as the check data generating part 21, with reproduced check data, and the number of errors is added to an adding circuit 26. Thus, if MODEMs are set to the error check mode shown in figure, the test of the route of MODEM-line-MODEM is performed automatically, and a degree of bit error generated in a prescribed period is seen on a display circuit. |
