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ALARMS, TROUBLESHOOTING & TESTING

 12

4. 3 Test Loop

 

Figure 4. 3 Test loop on local DC3445 

Set the local DC3445 base panel bit-switch labelled 

TEST LOOP  

to the 

ON 

position. When 

the 

TEST LOOP

 is activated at the local DC3445, the signal received at the LINE port is 

passed directly back to the link at the line interface. The signal from the DTE is looped 
adjacent to the DTE port. This effectively isolates the DC3445 running the test and validates:

(a) the local DTE cable if the local DTE recognises its own transmissions. 
(b) the remote DTE and its cable, the remote DC3445 and the LINE link if the remote DTE 
recognises its own transmissions.

Figure 4. 4 Test loop on remote DC3445

Set the remote DC3445 base panel Bit-switch labelled 

TEST LOOP  

to the 

ON 

position. 

The test loop validates:

(a) the remote DTE cable if the remote DTE recognises its own transmissions. 
(b) the local DTE and its cable, the local DC3445 and the LINE link if the local DTE 
recognises its own transmissions.

DC3445

DC 3445

LOCAL
  DTE

REMOTE
    DTE

Tx

DC3445

DC 3445

LOCAL
  DTE

REMOTE
    DTE

Summary of Contents for DC3445

Page 1: ...ce Village Eversley Way Egham Surrey TW20 8RY United Kingdom tel 44 0 1784 744700 fax 44 0 1784 744730 email support metrodata co uk Part No 76 02 046D website www metrodata co uk support Metrodata DC3445 User Manual DC3445 www metrodata co uk ...

Page 2: ...s display rear panel 4 Power Supply 4 Unbalanced E3 DS3 Line port BNC 5 Alarm Extension RJ45 5 HSSI DTE Port 6 3 INSTALLATION SET UP 7 Setting up the Bit switches 7 E3 DS3 Enable 8 Timing 8 Line coding 8 Test Loop 8 Connecting up 9 4 ALARMS TROUBLESHOOTING TESTING 10 Alarms 10 Troubleshooting 11 Test Loop 12 5 DC3445 SPECIFICATIONS 13 DC3445 Product Specification 13 DC3445 Clocking Diagram 14 Glos...

Page 3: ...The DC3445 interfaces an E3 service 34 368 Mbps or a DS3 service 44 736 Mbps and Data Terminal equipment presenting a High Speed Serial Interface HSSI The E3 DS3 selection is made by setting a bit switch mounted on the base of the unit DC3445 s are used in pairs one on either side of a WAN Wide Area Network link Figure 1 1 DC3445 installation LAN LAN ...

Page 4: ...ation This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance w...

Page 5: ...lso conforms with the following Common Technical Regulations 72 23 EEC Low Voltage Directive 89 336 EEC EMC Directive and EN 60950 Safety 1 8 1 Signal Transmission The signal is transmitted on 75 Ohm unbalanced coax The signal has alternate mark inversion AMI characteristics in accordance with G 703 A mark is transmitted as a 0 5 unit interval UI wide pulse of amplitude 2 37V 75 ohm Alternate mark...

Page 6: ...ternal fuse AC Mains power is connected via the IEC inlet on the rear of the unit An alternative 48VDC powered unit is available The input voltage and current ranges are minus 36 to minus 72 volts DC 150 70 mA A Buccaneer type socket is fitted to the rear panel and a plug is provided with the unit for the customer s own wiring The connections are labelled on the rear panel of the DC3445 On some un...

Page 7: ...y law 2 5 Alarm Extension RJ45 The alarm extension is an RJ45 female socket mounted on the rear panel of the unit It allows the connection of major and minor alarm relay contacts to a remote indicator such as a bell or a lamp The alarm relay port is regarded as a SELV port within the scope of EN41003 Mains power failure is registered via Normally Closed contacts as a major alarm Figure 2 6 RJ45 al...

Page 8: ...hould be used for connections to this port Note The HSSI port is regarded as a SELV port within the scope of EN 41003 Figure 2 7 HSSI port connector layout VEPin No VE Pin No Function CCT No 1 26 SG 102 2 27 RT 115 3 28 CA 107 4 29 RD 104 5 30 LC 6 31 ST 114 7 32 SG 102 8 33 TA 108 2 9 34 TT 113 10 35 LA 141 11 36 SD 103 12 37 LB 140 13 38 SG 102 14 18 39 43 Reserved 19 44 SG 102 20 23 45 48 Reser...

Page 9: ...igure 3 1 DC3445 Base Panel label Figure 3 2 Bit switch definitions Parameter Label Unit Options E3 DS3 E3 DS3 Enable Up Down DS3 or E3 Timing Clock select Position Internal or Loop Test Test Loop On Off Run Test Loop or No Test TEST LOOP OFF ON Serial No DC3445 E3 DS3 HSSI AC For product manual and other information www metrodata co uk Metrodata Ltd TW20 8RY UK Tel 44 0 1784 744700 Fax 44 0 1784 ...

Page 10: ...ng With INTERNAL timing selected Send Timing ST is derived from the DC3445 s own internal oscillator With LOOP timing selected ST is derived from the E3 DS3 LINE Receive clock The recommended timing mode for the DC3445 pair at either side of the WAN is Internal at one end of the link and Loop at the other end 3 1 3 Line coding This setting is automatically selected when the Line is selected no bit...

Page 11: ...he rear panel The DSU should ideally be placed close to the DTE with no more than 2m of cable connecting the two Step 3 E3 DS3 LINE WAN Connect the WAN by means either the two BNC bayonet connectors labelled LINE Rx and LINE Tx Step 5 Connect the Alarm device to the RJ45 outlet labelled ALARM EXT if you wish to make use of the audible visual alarm facility Step 4 Power Supply Finally connect the m...

Page 12: ... of each alarm and the unit s response to them is tabulated below Figure 4 2 Alarm definitions responses Status LED Meaning Off No mains power present Red steady LOS Red Off flashing LOS and DTE Alarm Green Off flashing DTE Alarm Green steady Status OK Alarm Alarm Definition Response LOS Loss Of Signal No data and therefore no clocking information LOS alarm signal from LED DTE DTE Control signal a...

Page 13: ...NC connections on the unit with a short piece of cable If the status LED goes steady green or flashes green off then the external BNC cabling is faulty Check for cable continuity and network connections etc Step 2 Establish and verify the DTE link If the status LED flashes GREEN OFF check that the local router port status is UP and that the local router cable is in place If problems persist check ...

Page 14: ...he test and validates a the local DTE cable if the local DTE recognises its own transmissions b the remote DTE and its cable the remote DC3445 and the LINE link if the remote DTE recognises its own transmissions Figure 4 4 Test loop on remote DC3445 Set the remote DC3445 base panel Bit switch labelled TEST LOOP to the ON position The test loop validates a the remote DTE cable if the remote DTE rec...

Page 15: ... Clocking options E3 DS3 LINE port Circuit 113 normally slaved to Circuit 114 DTE port Circuit 114 INTERNAL LOOP DTE Receive timing RT Circuit 115 is always sourced from the E3 DS3 Receive clock Diagnostics Loop Test initiated by Bit switch General Definition Power supply 100 250 VAC 50 60 Hz 115 45 mA or 36 to 72 VDC 150 70 mA Dimensions 202 x 132 x 44 mm w x d x h Enclosure only 202 x 132 x 47 m...

Page 16: ...DC3445 SPECIFICATIONS 14 5 2 DC3445 Clocking Diagram Figure 5 1 DC3445 Clocking diagram CCT 115 CCT 113 CCT 114 Line Tx Internal Osc 15 ppm ...

Page 17: ...he content hereof without obligation of Metrodata Ltd to notify any person of such revision or changes Trademarks The Trademarks of other Corporations which may be used in this manual are hereby ac knowledged Copyright 2006 by Metrodata Ltd All Rights Reserved AIS Alarm Indication signal AMI Alternate Mark Inversion B3ZS Binary 3 Zero Suppression DSU Data Service Unit DTE Data Terminal Equipment H...

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