| 摘要 |
<p>PURPOSE:To conduct a test for a transmission line even after an inhibit pattern appears by generating newly a transmission PN pattern based on an initial generating data when the inhibit pattern appears as a transmission PN pattern subjected to be in bit comparison with a loopback PN pattern. CONSTITUTION:The PN pattern generating section (A)1-1 of a device (A)1 sends a PN pattern to a transmission line 2, the pattern is looped back at a device (B) 3 and fetched by the device 1 via the transmission line 2. A PN pattern generating section (B)1-2 generates a same PN pattern as the sent PN pattern. The PN pattern from a PN pattern generating section 1-2 is normally subjected to bit comparison with the sent PN pattern subjected to loop back at comparator section 1-3 in phase synchronized state and the result is monitored as a bit error rate. In this case, when an inhibit pattern is generated, it is detected by an inhibit pattern detection section 1-4, an initially generated data as an initial set signal is loaded to the PN pattern generating section 1-2, and the PN pattern is newly generated based thereon to attain error measurement again.</p> |
