CANOGA PERKINS 3240S SNMP Managed Fiber Optic Multiplexer - Manual (Page 27)

3240S F I B E R O P T I C M U L T I P L E X E R
3240S Fiber Optic Multiplexer
2.3.4.2 MDSO Card Switch Settings
Switch SW3 on the lower board, as referenced in Figure 2-10, assigns global parameters for each card assembly.
• Position 1 - base frequency set to 56Kbps or 64Kbps
• Position 3 - high or low speed mode
• Position 2 and 4 - time slot allocation
2.3.4.2.1 Speed Setting 56Kbps or 64Kbps
Selection of 56 or 64Kbps as elected by the switch setting of position 1, or SW3-1, establishes that all channels on the card
must be operating at a frequency that is a multiple of either 56 or 64Kbps, not both. This causes some restrictions for each
board since all channels thereon must conform to the selected speed setting. (C)losed = 56K. (O)pen = 64K.
2.3.4.2.2 Low Speed Switch Setting
Low speed selection is required via switch setting 3, or SW3-3. All operating frequencies will fall into the low speed range of
frequencies thus the board should be set to low speed. If any of the frequencies fall into a frequency above the highest
frequency available through the low speed setting, then the board could be set to the high speed setting, though this
application is very specialized. When set to low speed, the board takes only one of the two time slots allocated to the MDSO.
Factory default for this switch setting is Low. Most users will never need to utilize the high speed switch position due to the
multiplexer's limitation of two physical card slots. Reference Table 2-C. (C)losed = High. (O)pen = Low.
2.3.4.2.3 Time Slot Assignment
As with other I/O cards, the total bandwidth available is divided into four equal segments, 1-4. Only one pair of cards can
share the same time slot, and a time slot can only be assigned to one card in each unit. That means that if another card is
already set for time slots 1 and 3, only time slots 2 and 4 are available for the MDSO. The MDSO must always occupy two time
slots. If one MDSO card is used, the other physical slot cannot be populated with another type of I/O Module Card.
Reference Table-2B for time slot settings.
2.3.4.3 MDSO Clock Mode Options
Each channel can be individually set to run from an internal Clock, External Clock, or from a Slave Clock, depending on the
application. The last two positions, 7 and 8, on the channel switch of the lower board determine which clock source is used.
Reference Table 2-C.
Switch Position Clock Mode
7 8
C C Internal Clock
O C External Clock
C O Slave Clock
O O Not Allowed
• SW-1 is for Channel 2
• SW-2 is for Channel 1
• SW-4 is for Channel 3
• SW-5 is for Channel 4
Table 2-C
MDSO Clock Mode
2-11