FourthRack G.703 Line Card User Guide
Contents
1. 703 line card is receiving correctly encoded data from the line interface equipment The amber C LED indicates that the FourthRack G 703 line card is set to clock master mode See set up section for setting the clock master mode The amber T LED will illuminate when the use of the Terminal Timing option is selected See set up section for setting the terminal timing mode The amber L LED will illuminate when the loop back condition is selected using either the internal jumper or when the LB switch is pressed closed 2 6 Clock master clock slave settings When using a FourthRack G 703 system in conjunction with a MicroMux G 703 or when using a FourthRack G 703 at either end of a 2048kbit s circuit in clear channel operation one of the units should be set to clock master The Fourthtrack Systems recommendation is to set the system that is closest to the network core to clock master and the unit that is closest to the subscriber customer site to clock slave 2 7 Data polarity and clock polarity settings The data transmitted and received on the G 703 side of the FourthRack G 703 could have originated on another piece of equipment It is not uncommon for the data to be inverted by G 703 terminating equipment The FourthRack G 703 has the option to invert or not invert the data transmitted and received on the G 703 port See the set up section for the default setting and changing the data polarity In some cases w2. position One or other option must be selected for the DTE interface to function Note that first revision FourthRack G 703 X 21 line cards include the V X link field and links must be made in the X position DTE interface status is readable by management however as the links in this field control signal termination and drivers they cannot be overridden by manangement Ident V left side X right side LK19 V 35 X 21 LK18 V 35 X 21 LK10 V 35 X 21 LK21 V 35 X 21 LK20 V 35 X 21 4 Specifications 4 1 On Board Master Clock Operating Frequency 2 048 Mhz 50 PPM 25 deg C 4 2 Network Interface Signals Specification The Network Interface conforms to CCITT specification G 703 and ETSI Open Network Provision for digital unstructured leased line D2048U Transmit 2 37 V into 75R 10 3 00 V into 120R 10 Min 8 dB Max 14 dB Output Pulse amplitude Return Loss Receive Sensitivity Below 0dB 2 4 V 10dB Loss of Signal Threshold 0 3V Return Loss 18 dB Allowable consecutive Zeros before LOS 190 bits 4 3 Network Connectors Two version of the FourthRack G 703 are available 75 Ohm Unbalanced 120 Ohm Balanced G 703 RJ45 Pin Function 1 amp 2 Rx pair from network 3 Shield reference point 4 amp 5 Transmit pair to network 4 4 Shield reference point Note that the Receive Shield reference point is taken to ground via a link field Fitting the j
3. Fourthtrack FourthRack G 703 Line Card User Guide Fourthtrack Systems Unit 11 Lowfield Green Caversham Park Reading RG4 6NZ England Telephone 0118 946 3061 Fax 0118 946 3091 Communications answers for the World Market Fourthtrack Systems FourthRack and MicroMux are trademarks of R J Barrett Fourthtrack Systems FourthRack G 703 Rev 1 1 1 Ref 502 588 001 1 Introduction The Fourthtrack Systems FourthRack G 703 line card is a derivative of the highly successful MicroMux G 703 The FourthRack G 703 has been engineered to reduce cost and increase functionality in this expanding sector of the market and thus enhance Fourthtrack s position as the market leading provide of G 703 Data Service Units DSUs It is designed to enable the connection of data communication systems to carrier services or private services such as microwave links that are presented as G 703 at 2Mbit s The standard model supports an X 21 DTE with 75 ohm un balanced G 703 termination The enhanced version can support both X 21 and V 35 DTE with 75 ohm un balanced termination Both versions are also available with 120 ohm balanced termination of the G 703 network connection The FourthRack G 703 line card is designed to be used in the FourthRack Chassis The FourthRack chassis is a next generation rack mount system that supersedes the MegaChassis with the FourthRack G 703 superseding the MicroMux SP 1 RM line card The FourthRack c
4. alent should meet this specification 2 3 Connection to a 120 ohm balanced G 703 E1 network IFor use on a 120 ohm balanced service connection should be made using the RJ45 connector on the front panel of the 120 ohm version of the FourthRack G 703 This is labelled as G 703 The pin out for the RJ 45 is as defined for ONP CTR 12 and is given in the specification section 2 4 Connecting to DTE Connection to the DTE is made using the 15 way D socket Versions of the FourthRack G 703 are available that support X21 or X21 and V35 The pinout is given in the specification section 2 5 Status Indicators and Loopback Control There are five LED status indicators on the front panel of the FourthRack G 703 line card Reading from the top of the front panel these are labelled P N C T and L There is a small recessed push button switch between the T and the L indicators labelled LB Pushing this switch enables the loop back test function Releasing the switch terminates the loop back test function The green P LED indicates that the FourthRack G 703 is receiving power from the FourthRack back plane The FourthRack chassis and the FourthRack G 703 support hot swap The FourthRack G 703 has a built in power up control system The P LED will illuminate a few seconds after the FourthRack G 703 line card is inserted into the rack and the back plane connection has been made The green N LED indicates that the FourthRack G
5. gement is supported by using a different power supply module that includes the management function One or two of the management enhanced power supplies may be used in the FourthRack providing resilience in both terms of power and the management function Note that the initial release of the FourthRack chassis is with un managed power supplies However the production release of the FourthRack G 703 line card is common to both managed and un managed FourthRack systems Fourthtrack Systems FourthRack G 703 Rev 1 1 1 Ref 502 588 001 Configuration parameters selected using LK4 may be overridden via FourthRack management Management selected configuration options are maintained in non volatile memory when the card is removed or when power is lost If set to read only the FourthRack G 703 will power up with the configuration defined by its LK4 settings If set to read write the FourthRack G 703 will power up with the configuration defined by management and saved in its non volatile memory For full details on the management functionality refer to the User Guide supplied with the rack 3 2 Interface selection on dual function X 21 V 35 version The enhanced version of the FourthRack G 703 line card can support both X 21 and V 35 DTE The DTE interface function is selected using a link field identified as V X It is located toward the front of the line card adjacent to the DTE connector Links in the V X link field are three
6. hassis has fourteen line card slots and two power supply slots one at each end of the chassis The FourthRack Chassis can be used with either a single power supply or dual power supplies for resilience Auto ranging self sensing AC power supplies and DC power supplies 48VDC are available Please refer to the FourthRack chassis documentation for further information 2 Installation On unpacking the FourthRack G 703 line card you should find the unit and this manual If there are any questions please refer to your supplier 2 1 Connection to a 75 ohm un balanced G 703 E1 network For use on a 75 ohm un balanced service connection should be made using the two B N C connectors on the front panel of the FourthRack G 703 These are labelled as Rx and Tx Your G 703 carrier service equipment may be labelled with transmit and receive The FourthRack G 703 RX port should be connected to the receive side of the carrier equipment The FourthRack G 703 TX port transmits carrier and this should be connected to the out bound port of the carrier service 2 2 G 703 75 ohm Cable Schedule Connections should be made using 75 ohm co axial cables with B N C connectors The co ax cables required are two off 75 ohm co ax cables of 5mm diameter which must be terminated in male BNC connectors The maximum cable attenuation must be 6db at 1024kHz The attenuation characteristics should follow the root f law Cable type RG59 or 2002 or equiv
7. hen using an X 21 interface the data received from the DTE may be mis aligned with the X 21 timing signal and this can cause errors This situation can usually be overcome by changing the polarity of the clock used to clock in the received data with respect to the X 21 timing signal T he FourthRack G 703 has the option to change the polarity of the clock used to clock in received data See the set up section for the default setting and changing the clock polarity 3 Set up 3 1 Jumper functions and default settings The start up configuration of the FourthRack G 703 line card is controlled by jumpers grouped in link fields The primary link field is identified as LK4 Itis located toward the rear of the line card adjacent to the back plane connector Ident Open Closed MCLK Clock Slave default Clock Master XINV TxD Clock Inverted TxD Clock Not Inverted default SW3 Reserved Reserved default LPBK Normal Operation Local and Remote Loop default Back DINV G 703 Data Inverted G 703 Data Not Inverted default MTTC XCLK Clocking TTC Clocking default TCLK TT Disabled default TT Enabled CINV RxD Clock Inverted RxD Clock Not Inverted default Sw9g Reserved Reserved default READ Management Read Write Management Read Only default Note that READ is labelled as SW10 on first revision FourthRack G 703 line cards The FourthRack is available with management The mana
8. umper LK3 connects Receive Shield to ground 4 5 DTE Connector Chassis 1 Orga 9 TXDB TXDA 2 e 10 mc nc 3 11 RXDB RXDA 4 0 e 12 INDB NDA 5 L e 13 CLKB ee See 14 TCB TICA 7 Le e 15 mc Ground 8 1L 15 way D type Socket 4 6 Environmental The FourthRack G 703 is designed to operate under the following conditions Ambient temperature in the range of 5 to 45 degrees Celsius Relative humidity of 10 to 90 percent non condensing Atmospheric pressure 86kPa to 106kPa Power requirement Powered via the FourthRack chassis
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