Nortel Networks BCM200, 400 4.0 manual Determining bus requirements

Chapter 8 Installing a media bay module (MBM) 111

Offsets are assigned using DIP switches 1, 2, and 3 on the MBM.

Note: MBMs that do not, or cannot, share DS30 buses always assign the offset as 0 (zero). As well, if the MBM requires more than one bus, such as the 4x16 or the DDIM, only the first DS30 is set on the DIP switches. The next consecutive DS30 bus is automatically assigned by the MBM.

Figure 65 on page 111 shows a DS30 broken down into four offset groups of four (single density) or eight (double density) lines each.

Note: When you enable a station MBM for double density, the line numbers double.

Figure 65 Offsets are part of DS30 channel line groups

Offsets have	Offset 0	1 DS30 bus
4 lines (single-density)	Offset 1
		16 lines/32 time slots (single-density)
8 lines (double-density)	Offset 2	32 lines/32 time slots (double-density)
	Offset 3

Determining bus requirements

Figure 66 shows the DS30 bus requirements of each MBM. Note the differences between MBMs set to single density and MBMs set to double density.

Note: If you choose a CTM8, DDIM, or 4x16, there are some restrictions on the offsets you can choose. Refer to the DIP switch settings in “CTM switch settings” on page 123 and “4x16 switch settings” on page 126 for details.

BCM200/400 4.0 Installation and Maintenance Guide