Westell IDR9186SB Intelligent High-Density T1 Office Repeater

Transcription

1 Section IDR-918-6SB-201 Equipment Issue Rev. A, March 2008 Westell IDR9186SB Intelligent High-Density T1 Office Repeater CLEI* Code: T1R5TAVAAA CONTENTS PAGE # 1 GENERAL APPLICATIONS CIRCUIT DESCRIPTION OPTIONS & FEATURES INSTALLATION REMOTE MAINTENANCE OPERATION TESTING & TROUBLESHOOTING CUSTOMER SERVICE WARRANTY & REPAIRS SPECIFICATIONS GENERAL 1.1 Document Purpose This document describes the Westell IDR9186SB Intelligent High-Density T1 Office Repeater, shown in Figure 1. Hereafter, the IDR9186SB will be referred to as the IDR". 1.2 Document Status Whenever this practice is re-issued or revised, the reason will be stated in this paragraph. This practice replaces practice , provides a general editorial update, and changes the company contact information. 1.3 Product Purpose and Description The Westell IDR** is an AT&T Technologies DDM+ mounting- compatible, Intelligent, Powering Office Repeater. The IDR, when powered from -48 VDC office battery supply, provides power for 60 ma bi-directional span lines. The IDR regenerates T1 signals received from the span. Westell s IDR provides enhanced maintenance capabilities including looping back T1 transmission signals toward the DSX or toward the Network Interface. 1.4 Product Mounting The IDR is typically mounted in an AT&T Technologies DDM+ mounting assembly or shelf (or equivalent) at a fiber hub location or at the customer premises. See Table 5 for the IDR dimensions. Figure 1. I D R S B 1.5 Product Features ARM PWR LPBK LB -I -V Front View of IDR9186SB The enhanced Westell IDR offers the following features. Metallic Loopback toward the DSX Logic Loopback toward the Network Interface (NI) Manual loopback capability toward the DSX Side 2 Receive Automatic Line Build-Out (ALBO) Switch-selectable, Span Powering option (POWER - LOOP); When set to POWER, provides span powering at 60 ma up to -130 VDC. When set to LOOP, the IDR functions as a local-powered looping repeater. Remote Span Power Disable Loopback Indication Signal (LIS) Automatic SF or ESF code detection Ability to toggle on and off the blocking of NIU Loopback Code when received from the NI Optional Alarm Indication Signal () upon Loss-Of-Signal (LOS) from the DSX or NI Repeater loopback query Copyright 2008 Westell, Inc. All rights reserved. *CLEI is a trademark of Telcordica Technologies. **IDR = Intelligent DDM+ compatible Repeater. Westell is a registered trademark of Westell, Inc. Page 1 of 9

2 Section IDR-918-6SB Rev. A Central Office Facility Customer Premises ORB IDR ILR7239 ILR7239 ILR7239 Metallic Network Interface Unit Customer Terminal Equipment (CSU) DDM+-Type Mechanics Demarcation Figure 2a. IDR Central Office Application, Powering Downstream Intelligent Line Repeaters (ILRs) and the Network Interface Unit Central Office Facility Customer Premises CEV or 80-Type Enclosure M1/3 Fiber MUX Fiber M1/3 Fiber MUX IDR ILR7239 Metallic Network Interface Unit Customer Terminal Equipment (CSU) DDM+-Type Mechanics Demarcation Figure 2b. IDR Outdoor Enclosure Application as a Fiber Extension Repeater Powering Downstream ILRs and the Network Interface Unit Figure 2. Typical IDR Applications 30-minute loopback time-out Power Loop Query; determines last repeater before cut cable Remote repeater identification capability Arming code for security Arming time-out, factory set for 30 minutes Loopback and query Bit Error Acknowledgments (BERs) repeated every 20 seconds Span current and voltage test points Front panel LEDs provide quick visual indication for: Fuse Alarm (), Power (PWR), Arming (ARM), and Loopback (LPBK) Meets all UL1459 Recognition requirements Lightning protection CAUTION - STATIC-SENSITIVE This product contains static-sensitive components! Proper electrostatic discharge procedures must be followed to maintain personal and equipment safety. Do not store units near magnetic, electromagnetic or electrostatic fields. Always store or ship units in the original static-protective packaging from Westell. Use anti-static mats when working on units. 2 APPLICATIONS Westell s IDR is used to provide High Capacity (Hi-Cap) Digital Service (HCDS) over metallic cable pairs that transport bipolar data at the DS1 rate (1.544 Mb/s). The IDR is typically located at a fiber hub location or at the customer premises. The IDR supports 60 ma bi-directional spans. T1 Span design, including repeater powering and end-section design, should be done in accordance with standard T1 span design or local company procedures. In addition to providing HCDS, Westell s IDR facilitates maintenance testing, and fault location by providing a maintenance loopback that can be activated toward the DSX or Network Interface. 3. CIRCUIT DESCRIPTION Refer to Figure 3, the IDR Block Diagram, as needed, while reading the following circuit description. 2

3 Rev. A Section IDR-918-6SB T FROM DSX IN R LLB LLB Lightning Protection MLB MLB T1 105 XMT TO SPAN 106 R1 117 Fuse Alarm Fuse Alarm Detector 3V Driver LLB S1 POWER LOOP V Automatic Span Power Regulator (ASPR) GND GND GND DC-DC Converter Open Loop Detector -I -V 10 Ohms 16-Bit Code Detector Generator Microprocessor Logic and Nonvolatile Memory Generator 16-Bit Code Detector S2 MLB PWR ARM LPBK S3 114 T1 115 R1 TO DSX OUT 3V Peak Output Driver LLB LLB Signal Regenerator ALBO Lightning Protection MLB MLB T 101 RCV FROM SPAN 102 R Figure 3. IDR Block Diagram 3.1 Transmit To Span (Side 1) Incoming T1 signals from the DSX are applied to the Side 1 FROM DSX IN" port, pins 109 and 110 (T&R). These signals are routed to the Side 1 Code Detector circuit. The Side 1 Code Detector monitors the incoming signal for maintenance control codes and a DSX Loss-Of-Signal (LOS). The signal is then transformer-coupled through the Lightning Protection circuit to the span line via the XMT TO SPAN" port, pins 105 and 106 (T1&R1). 3.2 Receive From Span (Side 2) T1 signals appearing on the Side 2 RCV FROM SPAN" port, pins 101 and 102 (T&R), pass through the Lightning Protection circuit. These signals are transformer-coupled to the Extended Range Automatic Line Build-Out (ALBO). The extended range ALBO circuit regenerates signals experiencing from 0 to 35 db of loss. The output of the ALBO is applied to the Side 2 Code Detector circuit. The Side 2 Code Detector circuit monitors the incoming signal for maintenance control codes and a Facility LOS. The Output Driver provides a 3 volt base-to-peak (6 volt peak-to-peak) output signal. The signal is then transformer coupled to the Side 2 TO DSX OUT" port, pins 114 and 115 (T1 & R1). 3.3 Loss-Of-Signal (LOS) Detection The IDR constantly monitors the incoming transmission from the Facility and the DSX for a LOS. The IDR can be optioned by Switch S3 to transmit an unframed all-ones Alarm Indication 3

4 Section IDR-918-6SB Rev. A Signal () toward the Facility or DSX upon detecting a LOS. When the signal is restored, the is no longer transmitted. 3.4 Span Powering Westell s IDR is equipped with an Automatic Span Power Regulator (ASPR) circuit. The IDR automatically provides the required voltage, up to -130 VDC, to power a 60 ma bi-directional span line from the -48 VDC battery supply. The IDR supports spans with up to 2160 Ohms of simplex resistance. Set any/all manual option switches prior to installing the unit. 4 OPTIONS & FEATURES The Westell IDR should be should be optioned prior to installation. The IDR contains two slide switches on the Printed Circuit Board (PCB) and a push button switch on the front panel that option the unit for proper operation in various applications. Also located on the front panel are four LEDs and two pin jacks. Refer to Figure 2 for the location and a brief description of each option and feature. - PRECAUTIONARY STATEMENT - Never install telephone wiring during a lightning storm. Never install telephone jacks in wet locations unless the jack is specifically designed for wet locations. Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the network interface. Use caution when installing or modifying telephone lines. - INSPECTION NOTE - If not previously inspected at the time of delivery, visually inspect the unit for damages prior to installation. If damaged in transit, immediately report the extent of the damage to the transportation company and to Westell (see Part 6 for telephone number). 4.1 S1 - POWER or LOOP Switch Switch S1 is used to enable or disable the ASPR. When set to POWER," the IDR provides span powering for downstream line repeaters, the DS1 Interface Connector (NIU), and when required, the Customer Terminal Equipment (CSU). When set to LOOP," the Span Power Regulator is off (no span power provided), and the simplex leads are looped. The LOOP position is useful in applications where the IDR is not required to power other network elements (e.g., when deployed as a local-powered looping repeater or as a Network Interface Unit). 4.2 S3 - /Off Switch This switch, when set to the position, transmits an Alarm Indication Signal () after detecting a LOS from the span or Network Interface (NI). When in the position, is not transmitted. 4.3 S2 - Manual Loopback Push Button Switch The IDR can be manually looped back toward the DSX by pressing the front-panel MLB push button switch. The IDR will remain in loopback until the MLB switch is reactivated or the appropriate loopdown code is received. Manual loopback does not time out. 4.4 LEDs LPBK (Loopback) LED The IDR is equipped with a front-panel yellow Loopback (LPBK) LED. When loopback is activated toward the DSX, the LPBK LED lights steady. When loopback is activated toward the Network Interface, the LPBK LED flashes PWR (Power) LED - Input Power Indication The IDR is equipped with a green PWR (Power) LED. The PWR LED lights when -48 VDC office battery and battery return ground are present on pins 217 and 218; the internal power supply is functioning properly, and span current is flowing. When Switch S1 is in the LOOP position or if an open power loop exists, the PWR LED will pulse at 1-second intervals. When the IDR is placed in the remote, Temporary Power Down mode, the PWR LED flashes. If the PWR LED is not lit, -48 VDC is absent ARM (Arming) LED The IDR is equipped with a yellow ARM (Arming) LED which lights after the IDR has received the code for 5 seconds or longer. The IDR can operate on command codes when it is in the armed state (Alarm) LED and Input Power Fuse The IDR is equipped with a built-in, non-field-replaceable ¾-Amp fuse. The (Fuse Alarm) LED lights when the fuse opens and when the IDR is in open power loop mode. 4.5 Pin Jacks - Span Current and Voltage The IDR is equipped with 2 pin-type test jacks that are used for monitoring span current and span voltage. Span current is measured as a voltage across the -I and -V jacks. The voltage measured across the pin jacks should be between.57 and.63 VDC which equates to a span current of 57 to 63 ma. The span current should be balanced within 2%. Span voltage is measured by inserting one probe of the volt meter into the -V pin jack and referencing the second probe to ground. The span voltage measured should be consistent with the calculated span voltage. 5. INSTALLATION The IDR mounts in an AT&T DDM+ (High Density) T1 mounting assembly or shelf, or equivalent, at a fiber hub location or at the customer premises. See Table 1 for pin-outs. 4

5 Rev. A Section IDR-918-6SB CAUTION - Use care when installing and removing modules - do not force a module into place. If a module resists insertion, remove it and check for obstructions in or near the module s or shelf s connectors and mounting slots. The module may then be carefully aligned and gently re-inserted. LEAD DESIGNATION PIN Side 1 Input T From DSX In (Tip) 109 R From DSX In (Ring) 110 Side 1 Output T1 XMT To Span (Tip) 105 R1 XMT To Span (Ring) 106 Side 2 Input T RCV From Span (Tip) 101 R RCV From Span (Ring) 102 Side 2 Output T1 To DSX Out (Tip) 114 R1 To DSX Out (Ring) 115 Power -48 VDC Office Battery 217 Ground Battery Return 218 Fuse Alarm* 117 * The Fuse Alarm Output, pin 117, provides a -BATT output when the PCB-mounted fuse opens. Table 1. Installer Connections, Pin Assignments 6. REMOTE MAINTENANCE OPERATION Refer to Table 2, IDR Loopback Activation and Maintenance Control Codes), and the following paragraphs for a description of the remote maintenance capabilities of the IDR. All codes are transmitted LEFT-most-bit first with the exception of the ESF Data Link codes which are transmitted RIGHT-mostbit first. 6.1 Arming The Span Line The tester must first arm the span line before an IDR can be remotely accessed for maintenance testing Arming from the DSX Inband code: = > 5 sec. ESF Data Link code = > 16 ms The IDR is armed from the DSX by sending the Inband Arming code (framed or unframed) for greater than five seconds or the 16-bit ESF Data Link Arming code for greater than four repetitions (or 16 ms.) Arming From The Network Interface (NI) ARM code = > 5 seconds The IDR is armed from the NI by sending the Inband Arming code (framed or unframed) for greater than five seconds. Upon receiving the Arming code, the IDR s front-panel ARM LED lights. The IDR remains armed for 30 minutes unless the All Loopdown and Disarm code is received. The IDR allows the arming code to be sent through the unit towards the far-end NIU. Blocking of the arming code can be enabled. The arming state and loopback both time out after 30 minutes Arming Code Blocking Toggle Activate from: NI - Span Line Armed Activate code: > 5 sec. Once the IDR has been armed, sending the Arm Blocking Toggle Code (C56A Hex) from the CPE or the DSX enables or disables the blocking of the Arming code. The IDR is shipped with the Arming code blocking function disabled. When the function is enabled and the IHR receives Arming code for three seconds from the Network Interface side, the IHR sends an unframed all-ones Alarm Indication Signal () to the DSX to block the arming code from disrupting other network elements in the path. 6.2 Loopback Loopback allows the tester to rapidly sectionalize a problem in the span line by looping back test signals at various repeater locations. Loopback can be activated from either the DSX or from the Network Interface. When loopback is activated from the DSX, the IDR provides a Metallic loopback. When loopback is activated from the Network Interface, the IDR provides a Logic Loopback Metallic Loopback (MLB) Metallic Loopback (MLB) is activated and monitored from a test location on the DSX-side of the IDR. The metallic loopback point is on the span side of the IDR. Metallic loopback allows testing of all components, including the Span side transformers and lightning protection circuitry Logic Loopback Logic Loopback (LLB) is activated and monitored by a field technician at the Network Interface. Logic Loopback is an electronic loopback located before the output transformers and lightning protection. The span line remains powered during loopback Loopback Activation Activated from: DSX or NI - IDR Armed Activation code: > 10sec. To activate the IDR loopback, transmit the 16-bit loopback activate code for greater than 10 seconds while the IDR is armed. Loopback will automatically time-out in 30 minutes Loopback Indication Signal (LIS) The IDR transmits an unframed, all-ones Loopback Indication Signal (LIS) toward the Network Interface after loopback has been activated from the DSX. When Loopback is activated from the Network Interface location, LIS is sent toward the DSX. 5

6 Section IDR-918-6SB Rev. A Control Code to Transmit Command or Binary Code Hex Duration Unit Action / Results Function Code Sent/Reps Arming from DSX Inband > 5 sec. Repeaters arm and NIU loopback is activated. When armed, IDR s yellow ARM LED lights and ILR(s) red ARM/LPBK LED flashes. If NIU enters FF > 4 reps. loopback, pattern sync is recognized at T1 test location. Arming timeout = ESF Data Link 30 minutes. Arming from NI Inband > 5 sec. Near-end IDR and ILR(s) arm. When armed, IDR s yellow ARM LED lights and ILR s red ARM/LPBK LED flashes. Note: After receiving arming code for three seconds, the IHR could block the inband code from arming far-end repeaters and looping back the NIU. Arming timeout = 30 minutes. Arm Blocking Toggle C56A > 5 sec. While armed from the near-end NI, the blocking of the arming code from reaching the far-end can be enabled and disabled by sending this toggle code for greater than 5 seconds. Factory default has the blocking disabled. The IDR maintains the status of the blocking function, and follows that selection until it is again changed. IDR Loopback D3D3 > 10 sec. After 5 seconds, IDR enters loopback, sends loopback code for 5 seconds followed by 231 logic errors (loopback acknowledgment sequence), lights yellow LPBK LED (if loopback is initiated fromdsx side) or flashes LPBK LED (if loopback is initiated from NI-side) and sends LIS. Loopback time-out = 30 minutes. Loopback Query D5D5 > 20 sec. First repeater in loopback receiving Loopback Query code responds with Loopback Acknowledgment sequence. Power Loop Query B5B > 10 sec. from DSX Power Down > 5 sec. from DSX Loopback Deactivate > 5 sec. per repeater Armed IDR in Power Loop enters loopback, sends Loopback Acknowledgment. Loopback time-out = 30 minutes. Armed IDR receiving Power Down Code powers down the span and flashes green PWR LED. IDR remains in Power Down mode for 5 seconds after Power Down code is removed. Repeaters in loopback loopdown (loopback deactivates) but do not disarm after receiving the Loopback Deactivate code. All Loopback Inband > 5 sec. Repeaters in loopback loopdown and disarm after receiving the Inband All Deactivate & Loopdown & Disarm code from the NI side. Disarm ESF Data Link 24FF > 4 reps. Repeaters and NIU in loopback loopdown (loopback deactivates) and disarm after receiving the Inband or ESF Data Link All Loopback Deactivate & Disarm code from the DSX side. *Bit errors are repeated every 20 seconds until the code is removed. All codes transmitted LEFT-most-bit first except ESF Data Link codes which are transmitted RIGHT-most-bit first. Table 2. Remote Maintenance and Provisioning Control Codes and Queries Loopback Acknowledgment (DSX or NI) Loopback Acknowledgment is the method used by the IDR to verify that the unit has entered loopback or has successfully completed any of the other remotely-accessible features. During loopback activation, the IDR sends/performs the following Loopback Acknowledgment, toward the direction loopback is activated: after receiving loopback activate code for 3 seconds, the IDR returns 2 seconds of (Alarm Indication Signal), IDR then enters loopback and returns 5 seconds of unerrored Loopback Activate code, IDR then injects 231 bit errors into the looped-back T1 transmission, IDR then returns Loopback Activate code, until the code is removed. 6.3 Queries Loopback Query Activated from: DSX or NI Activation code: > 20 sec. Loopback Query allows the tester to determine which Intelligent repeater (if any) is in loopback. The T1 span can be queried from the DSX or from the Network Interface. The side requesting the query sends the 16-bit Loopback Query code (D5D5 Hex) for greater than 20 seconds. Upon detecting the query code, one of the following responses is returned: no pattern sync - indicates no loopback exists continuous pattern sync - indicates the NIU has looped back or there is an existing loopback. pattern sync and 10, 20, bit errors - indicates address of an Intelligent Line Repeater in Logic Loopback A response of 15,25, bit errors indicates the address of an Intelligent Line Repeater in Metallic Loopback. 6

7 Rev. A Section IDR-918-6SB-201 A response of 231 bit errors indicates an Office Repeater in loopback Open Power Loop Query Activated from: DSX - Span Line armed Activation code: > 10 sec. The tester can query the span line to determine if an open power loop exists and where it is located. An armed IDR in the Open Power Loop mode will enter loopback after receiving the 16-bit Power Loop Query code (5B5B Hex) for greater than 5 seconds. The IDR, upon entering loopback, will transmit its Loopback Acknowledgment bit-errors, identifying the location of the power loop. 6.4 Power Down Activated from: DSX - IDR armed or loopback activated Activation code: > 5 sec. An armed IDR can be remotely commanded from the DSX to disable the span power. This is accomplished by sending the Power Down code for greater than 5 seconds while the IDR is armed or in loopback. The PWR LED flashes. Power to the span line remains disabled until the Power Down code is removed. Five seconds after the code is removed, span power is restored, and the IDR disarms and goes idle. 6.5 Loopback Deactivate Activated from: DSX or NI Activation code: > 5 sec. Loopback can be deactivated before the 30-minute time-out by sending the 16-bit loopback deactivate (IDR LPDN) code (9393 Hex) for greater than 5 seconds. The repeater(s) remain armed. Each time the repeater returns to the armed state, the 30-minute arming timer resets. The tester can either activate another repeater for testing or can re-activate the same repeater if further testing is not required. 6.6 All Loopback Deactivate & Disarm from DSX Inband code = > 5 sec. ESF DL code = > 16 ms Sending the Inband All LPDN and DISARM code for greater than 5 seconds or the 16-bit ESF Data Link All Loopdown and Disarm code for greater than 4 repetitions from the DSX deactivates all loopbacks, including the NIU, disarms the span line, and returns the circuit to normal. 6.7 All Loopback Deactivate & Disarm from the NI Inband code = > 5 sec. Sending the Inband All LPDN and DISARM code for greater than 5 seconds from the NI deactivates the repeater loopback, disarms the span line, and returns the circuit to normal. 7. TESTING & TROUBLESHOOTING 7.1 Testing After installation is complete, initial testing consists of using the maintenance control codes listed in Table 2 or by performing the procedures outlined in Table 3. These procedures are intended only to ascertain proper operation of the unit and if problems should occur, to isolate those problems to the most probable area. These procedures are not designed to effect repairs or modifications. Tests beyond those outlined, or repairs made beyond replacing a faulty unit, are not recommended and may void the warranty. Step Task/Action Result/Response From the DSX 1. Send inband arming code (NIU Loopback code) (left-most bit first; framed or unframed format) for > 5 seconds or the ESF Data Link Arm code for > 4 repetitions. 2. Put the IDR in loopback by sending the loopback code for > 10 seconds. Tester can monitor for the return of pattern sync indicating the DS1 Inteface Connector is in loopback. Arming timeout is 30 minutes. IDR enters loopback and sets a 30-minute timer. 3. Send test patterns for span integrity testing. Monitor for errors in return path. 4. Send the inband loopdown and disarm code (left-most bit first) for > 5 seconds or the 16-bit ESF Data Link loopdown code for > 4 repetitions. From the Network Interface 1. Send inband arming code (NIU Loopback code) (left-most bit first; framed or unframed format) for > 5 seconds. 2. Put the IDR in loopback by sending the loopback code for > 10 seconds. All equipment, including NIU, returns to normal operation. Arm IDR. Arming timeout is 30 minutes. IDR enters loopback and sets a 30-minute timer. 3. Send test patterns for span integrity testing. Monitor for errors in return path. 4. Send the inband Loopdown and Disarm code (left-most bit first) for > 5 seconds. Table 3. IDR Test Procedures All equipment, including NIU, returns to normal operation. 7

8 Section IDR-918-6SB Rev. A 7.2 Troubleshooting If trouble is encountered, verify all installer connections to the assembly and check that the CO power fuse is not blown. Check the module connections and option switch settings, and verify the module is making a positive connection with the shelf connector. If trouble persists, replace the unit and repeat procedures outlined. 8. CUSTOMER & TECHNICAL SERVICES If technical or customer assistance is required, contact Westell by calling or using one of the following options: Voice: (800) global_support@westell.com For additional information about Westell, visit the Westell World Wide Web site at 9. WARRANTY & REPAIRS 9.1 Warranty Westell warrants this product to be free of defects at the time of shipment. Westell also warrants this product to be fully functional for the time period specified by the terms and conditions governing the sale of the product. Any attempt to repair or modify the equipment by anyone other than an authorized Westell representative will void the warranty. 9.2 Repair and Return Westell will repair or replace any defective Westell equipment without cost during the warranty period if the unit is defective for any reason other than abuse, improper use, or improper installation. To return defective equipment, first request a Return Material Authorization (RMA) number from Westell by calling or using one of the options shown below. Once an RMA number is obtained, return the defective unit (freight prepaid), along with a brief problem description, to the address we will provide to you when you contact us. Voice: (630) rgmdept@westell.com Replacements will be shipped in the fastest manner consistent with the urgency of the situation. Westell will continue to repair or replace faulty equipment beyond the warranty period for a nominal charge. Contact Westell for details. 10. SPECIFICATIONS 10.1 Ordering Specifications To order units, call the telephone number shown in Part 8 and specify the part number shown in Table 4. Model # Part # Description IDR9186SB 9186SB DDM+ type, intelligent high-density T1 powering office repeater with loopback. CLEI* Code: T1R5TAVAAA. Barcode: *CLEI is a trademark of Telcordia Technologies. Table 4. Ordering and Option Information 10.2 Electrical and Physical Specifications The electrical specifications are listed below, and the physical specifications are shown in Table 5. Transmission Signal A. Repeater Operation: Passive transmit; Regenerative receive B. Line Impedance: 100 Ohms at 772 khz. C. Automatic Line Build-Out (capture range): 0 to 35 db of loss. D. Line Rate: Mb/s (±200 b/s). E. Pulse Height: 2.7 V to 3.3 V. F. Line Signal Pulse Width: 324 nsec. (±30 nsec.). G. DC Span Current: 60 ma (±3 ma). H. Span Voltage Range: up to -130 VDC (balanced). I. Line Current Regulation: ±0.5 percent at supply voltages of -42 to -56 VDC (-48 VDC, typical input). J. Current Drain: 235 ma at -48 VDC, maximum. K. Fuse Protection: ¾-Amp; Fuse is not field replaceable. Physical Feature U.S. Metric Height 3.5 in. 8.9 cm Width 0.7 in. 1.8 cm Depth 9.8 in cm Weight (approx.) 12 oz. 340 g Operating Temp. -40 to 149 F -40 to 65 C Humidity Mounting Table 5. 0 to 90% (non-condensing) One position of AT&T DDM+ Shelf Physical Specifications 8

9 Rev. A Section IDR-918-6SB-201 S1 POWER LOOP J J2 ARM PWR LPBK S2 J5 I D R S B LB -I J6 -V S3 US PAT NO XXXXXXX Switch Option Position/Label Function/Description Switch Option Position/Label Function/Description S1 POWER POWER POWER LOOP LOOP LOOP Enables 60 ma span power. Disables span power and loops the simplex leads. S3 Transmits after detecting a LOS from the Span or NI. Does not transmit upon LOS. Feature (Front Panel) Label Function/Description On when fuse is open or unit is in Power Loop mode (fuse is not field replaceable). LEDs PWR PWR On when unit is powered and span current is flowing. Pulses (slowly) when unit is powered but no span current is flowing. Flashes (rapidly) when unit is in a power-down mode. ARM LB ARM On when unit is armed. Off when unit is not armed. Pushbutton Pin Jacks LPBK LB -I -V On when loopback is activated toward the DSX. Flashes when loopack is activated toward the NI. Off when loopback circuit is deactivated (normal operating mode). Push to activate permanent IDR loopback toward DSX; push again to deactivate. -I and -V pin jacks are used to measure simplex current. -V pin jack and ground are used to measure span voltage. Note: Voltage should measure 0.57 to 0.63 volts (57 to 63 ma). Figure 4. Switch Options and Front Panel Features 9