| 摘要 |
PURPOSE: An automatic changeover switching system of an ADM by using a PLD and a method therefor are provided to provide a self APS test function and allow a user to change a working mode arbitrarily by controlling the working mode and a protect mode of an automatic changeover switch manually by using a PLD when an ADM equipment is used. CONSTITUTION: A push button switch(40) changes an automatic changeover switching mode by a user. A PLD(30) receives a control signal from the push button switch(40), requests an IRQ(Interrupt Request) from a CPU(20), receives an IACK(Interrupt Acknowledge) from the CPU(20) and forcefully changes a bit content of K1, K2 type of a frame coming in the current mode for a signal suitable to a code desired by the user. The CPU(20) executes an ISR(Interrupt Service Routine) suitable to the IRQ transmitted from the PLD(30). An ADM(10) includes an APS(Automatic Protection Switch) controller(13) for controlling according to a signal transmitted from the PLD(30) and an OHT(Overhead Terminator)(15) for reading a received signal. |
