Cabletron Systems 24 User Manual

Ring SequencePage 2-9Note: When cancelling a MIB override, the user may have to performthe switch and power-cycle procedure twice (as described in the stepsbelow) to actually change the STH hub’s ring speed by the switch.To return to switch control from an MIB overridden Ring Speed setting:1. Regain switch control. Change the current switch setting and power-cycle the STH. Regardless of the final desired speed, the user musttoggle the switch opposite its current position and then power-cyclethe STH to put a switch-position change into effect, cancelling theMIB override.2. Select the desired ring speed. If the Ring Speed switch setting is notyet the desired setting (it may be the same as the former setting fromthe MIB command), the user must again change the switch settingand power-cycle the STH to complete the change from the MIB-commanded speed setting to the desired switch-set speed setting,2.6.2 Ring SequenceWhen STH hubs are stacked, they are interconnected via the intelligenthub to create a larger ring network. The ring sequence for the stations onthe ring (the order in which stations are logically arranged on the ring) isdetermined by the physical location of each TCU connection in the stack.It progresses in ascending stack number and port number order. Thesequence is changed each time a station is inserted or de-inserted from aring.To determine the ring sequence, consider only those ports inserted intothe ring. Begin with the STH numbered lowest in the stack and list (inascending numerical order) the number of each inserted port. Repeatedlymove to the next STH and list the inserted ports in numerical order untilall ports inserted into the ring have been listed. The order is continuous,wrapping directly from the stack’s last inserted port to the first—from thebottom of the list, right back to the top.2.6.3 Power Supply RequirementsNote: The STH has a universal power supply which will accept inputpower from 90 to 264 VAC, 47-63 Hz.The power supply has two outputs of +5 volts and +12 volts. Themaximum output power is 20 watts and the minimum efficiency is 65%