Putting CHPIDs Offline/Online

     When the IBM FE is working on a tape drive, it is usually advisable to put the CHPID offline, to prevent the CHPID from communicating with the mainframe while IBM is fixing and testing.
     This is done via the console commands as follows:

Example - IBM wants to repair drive 300:

     V 300-301,OFFLINE
          Put both tape drives Offline
     D U,,,300,2
          Verifiy both actually went Offline.
     V PATH(300-30F),0A),OFFLINE
          This puts offline the path to those devices thru that CHPID
          Only have 2 devices but 16 are defined and must be in PATH command
          This puts the CHPID Offline. IBM can do it's thing.

   When IBM is done:
          This puts the CHPID back online
          This should also put the PATH back Online
     V 300-301,ONLINE
          This puts the devices back Online

For the other tape drives, adjust the addresses and CHPIDs as appropriate:
     Drives 310-311 are on CHPID 1A
     Drives 320-321 are on CHPID 11

If an address will not go Offlne, enter S XXX then do the D U,,,aaa,2 again to see if it went offline
If not, do D U,,ALLOC,aaa,2 to see what job is allocated to device 'aaa' and cancel that job.