Nortel Networks 400 4.0 User Manual
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Chapter 8 Installing a media bay module (MBM)
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Assigning DS30 resources
MBMs are assigned to DS30 buses in a specific hierarchical manner. This section describes the
preferred order of positioning for each type of MBM.
preferred order of positioning for each type of MBM.
The following are some general notes about assigning MBMs:
•
The DIP switches on the DDIM are used to set the DS30 designation for the DTM part of the
MBM. The MBM automatically assigns an additional DS30 for the data part of the DDIM.
You cannot choose DS30 7 for the DDIM because the data MBM would not be accessible. The
same applies to DS30 6 if your system is set to a 3/5 split. Refer to
MBM. The MBM automatically assigns an additional DS30 for the data part of the DDIM.
You cannot choose DS30 7 for the DDIM because the data MBM would not be accessible. The
same applies to DS30 6 if your system is set to a 3/5 split. Refer to
.
•
If you chose a 3/5 bus split for your system, DS30 7 cannot be used by any MBM. For MBMs
that require two buses, this means that you cannot set the DIP switches to DS30 6 for those
MBMs because the second level of lines falls into DS30 7, which is not accessible (see
that require two buses, this means that you cannot set the DIP switches to DS30 6 for those
MBMs because the second level of lines falls into DS30 7, which is not accessible (see
).
•
Refer to
for more information about 2/6 and 3/5
DS30 bus splits.
•
DSM32 MBMs require two DS30 numbers. When you assign the first DS30 number to a
DSM32, the MBM automatically adds the next DS30 number. For example, if you assign
DS30 2 to a DSM32, it uses DS30 2 and 03. However, you cannot choose DS30 7 for the
DSM32 because the second level of DSM lines would not be accessible. The same applies to
DS30 6 if your system is set to a 3/5 split. Refer to
DSM32, the MBM automatically adds the next DS30 number. For example, if you assign
DS30 2 to a DSM32, it uses DS30 2 and 03. However, you cannot choose DS30 7 for the
DSM32 because the second level of DSM lines would not be accessible. The same applies to
DS30 6 if your system is set to a 3/5 split. Refer to
.
•
DSM 32+ MBMs can be set to either single or double density. When they are set to double
density, the MBM only requires one DS30 bus.
density, the MBM only requires one DS30 bus.
•
The DIP switches on the 4x16 are used to set the DS30 designation and offset for the CTM
part of the MBM. The MBM automatically assigns the first half of the next bus for the 16
DSM lines. However, you cannot choose DS30 7 for the 4x16 because the DSM lines would
not be accessible. The same applies to DS30 6 if your system is set to a 3/5 split. Refer to
part of the MBM. The MBM automatically assigns the first half of the next bus for the 16
DSM lines. However, you cannot choose DS30 7 for the 4x16 because the DSM lines would
not be accessible. The same applies to DS30 6 if your system is set to a 3/5 split. Refer to
•
The CTM8 uses two offsets on a DS30 bus. You assign the first offset to the MBM, and the
second offset is automatically selected. This means that you can choose offset pairs 0-1, 1-2,
or 2-3. Because the MBM requires two offsets on the same DS30, you cannot select offset 3.
Refer to
second offset is automatically selected. This means that you can choose offset pairs 0-1, 1-2,
or 2-3. Because the MBM requires two offsets on the same DS30, you cannot select offset 3.
Refer to
•
Not all MBMs are available to all systems. Refer to
for specifics about each MBM.
Note: Remember, if you have chosen a 3/5 bus split for your system, DS30 bus 7 is no
longer available for MBMs.
longer available for MBMs.