Cabletron Systems TRMIM 24A TRMIM-24A User Manual

Also see for TRXI-22A: Addendum

Contents

INTRODUCTIONPage 1-3You can upgrade the TRXI-22A and TRXI-42A to twenty-four portsusing a twelve port upgrade kit available from Cabletron Systems(Cabletron Part Number TRXI-24A-UGKIT or TRXI-44A-UGKIT).The TRXI provides two additional ports for Ring In and Ring Out(RI/RO) connections. These ports support Cabletron’s Token Ring PortInterface Modules (TPIMs). TPIMs provide full repeater functionality.They are not included with the TRXI, but can be ordered separatelyfrom Cabletron. Table 1-1 lists each TPIM.1.4 TRXI FEATURESActive TCU PortsThe active TCU ports regenerate, reshape and filter the incomingsignal permitting UTP lobe cable lengths of up to 100 meters and STPlobe cable lengths up to 150 meters at 16 Mbps ring speed.Cable Signal PolarityDifferential Manchester encoding is utilized for each of theconcentrator module TCU ports. This permits passing data regardlessof receive link polarity.Note: If a reversed polarity condition is discovered, the segment shouldbe removed from the network and wired correctly (according to theconnector wiring shown in Chapter 2, Requirements / Specifications).This will avoid the potential for future compatibility problems.Speed Fault ProtectionIf a station attempts to insert into the ring at a ring speed(4 or 16 Mbps) different from what is set on the TRXI, that port isautomatically bypassed to prevent the ring from beaconing. The LobePort Status LED blinks indicating the port with the speed fault isbypassed.Local ManagementLocal Management provides the tools to manage the TRXI and all ofits attached segments. You access Local Management by connecting aDigital Equipment Corporation VT™ 320 series terminal or a PCusing VT320 emulation software to the TRXI’s COM 1 port.