Model 7976 Switchpack Definitions
Table 20
through Table 22 list Model 7976 Switchpack definitions.
Table 20. Switchpack S4 Definitions (Model 7976)
Switch # . . .
1
2
3
4
5
6
7
8
Allows you to . . .
Enable or disable Switchpacks S3 and S4.
OFF = Switchpacks Disabled
ON = Switchpacks Enabled
Control line termination.
OFF = 120 Ohm
ON = 75 Ohm
Select the unit's primary timing source. Valid only for a unit
configured as the LTU.
OFF = Internal Clock
ON = External Clock
Control the unit's E1 line coding.
OFF = HDB3
ON = AMI
Determine whether the unit will use G.704 framing. Unframed mode
(ON) is valid only when Switches 3–5 of Switchpack S3 are set to
full rate (all Off).
OFF = Framed
ON = Unframed
Enable CRC-4 generation and monitoring. Valid only for a unit
configured as the LTU. The NTU is automatically configured to
match the LTU setting.
OFF = Disable CRC-4 generation and monitoring
ON = Enable CRC-4 generation and monitoring
Control whether Channel 16 contains signaling information or data.
OFF = Channel 16 is used for signaling (voice mode)
ON = Channel 16 is used for data (data mode)
Not used
33
Default in Bold