| 摘要 |
<p>PURPOSE:To make it possible to detect an error block of a receiving station and also to resend the error block by dividing a messages into blocks and then by adding a check code to each block for transmission. CONSTITUTION:Multiple address message 7 is divided into blocks 81-8n, each block is given block check code 11 and numbered 10 in sequence, and they are transmitted, block by block, from transmitting station 1. At every time when each block 8 of multiple address message 7 is received, each receiving station 4 checks the existence of an error on the basis of code 11 and when the error is detected, a negative acknowledge signal for a resending request is returned to transmitting station 1 via a different line. On receiving the negative acknowledge signal, transmitting station 1, sends a corresponding block back and receiving station 4, when receiving a block with an accurately-received number, ignores the block.</p> |
