Nortel DMS-100 Series General Description Manual

Also see for DMS-100 Series: User guide Product guide Manual Maintenance manual Maintenance manual

Contents

Nortel DMS-100 Series General Description Manual Manual pdf 61 page image

Ringing in Series I peripherals 2-3DMS-100 Family DMS-100 Ringing System BASE15 and up• synchromonic MF - NT2X27AE• 20 Hz BOC coded ringing (105 V RMS) - NT2X27AFThe RGI card also monitors ring generator output levels and reports anyproblems to the line module controller (LMC) through the signaling processor(SP).Line module power converterThe ring generator is actually part of a LM/RLM power converter. The powerconverter supplies both a regulated +24V for use in the LM/RLM shelf and aprogrammable ac/dc voltage. The programmable source is capable ofproducing ac or dc outputs at a wide range of voltages and frequencies. Theprogrammable source is the ring generator portion of the power converter.The ringing generator receives a pulse-width modulated drive signal from theRGI. The drive signal drives a 4-transistor balanced-bridge amplifier thatdrives the ringing bus in the LM/RLM shelf. The amplifier bridge is balancedfor a drive signal of 50 percent duty cycle (50 percent on, 50 percent off)results in zero output.Output voltage magnitude, polarity, and frequency are controlled by the dutycycle and frequency of the drive signal from the RGI.Ring multiplexerThe ring MUX multiplexes the outputs of the ring generators onto the linedrawer internal ring bus. Each line drawer has a ring MUX(NT2X20/NT2X02). The ring MUX receives messages from the LM/RLMcontroller through the signal processor instructing it to connect the line drawerinternal ring bus to the appropriate ring generator.Ring busThe ring bus brings the ringing signal to all of the line cards in the line drawer.A ringing relay on each line card attaches and detaches the subscriber tip orring lead to the ringing bus under the control of the LM/RLM controller so thatringing voltages can be applied.LM and RLM ringing processThe LM and RLM contain several processors that carry out call processingtasks under the direction of the DMS-100 central control (CC). The followingdescribes the processors associated with ringing and the tasks they perform inthe ringing process.