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TB001 Identifying Master & Slave Mixups on HY-II 64 Port Units

 
                  J.D.S. MicroProcessing Technical Bulletin
DATE WRITTEN:  02/08/89                    SUBMITTED BY:  R. SANDE
     SEQUENCE:  1 OF 1                            FILEID: TB001 BULLETIN

            Identifying Master & Slave Mixups on 64 Port Units
            

     When a customer installs an interconnect 64 port unit dual chassis
 he is seldom aware of which box is the master and which box is the slave
 unit. Occasionally he may notice that the cuu addresses are backwards
 when he attempts to do a DSPLY CNFG on the unit.

 FOR EXAMPLE: if the first half of the 64 port unit was cuu address 500
              and the second half was assigned cuu address 520 they may
              appear like this:

    CUU    PORT                                  CUU    PORT
                                              
    020     00     ...........................   000     20
    021     01     ...........................   000     21
    022     02     ...........................   000     22
    023     03     ...........................   000     23
    etc.........                                 etc...........

     This condition is caused because the HYDRA MASTER unit is always
 interrogated first. The reason for this is that the interconnect board in this master unit is the only one out of all four boards that contains memory.

 Knowing this, you can always identify which unit is the master and
 which is the slave when requesting a maintenance unit from production.