Zhone Technologies IMACS-200 - Manual (Page 193)

High Speed Data Ports 9-5
Figure 9-2.HSU Port Time Slot Assignment Screen
RATE
The Rate setting allows you to select the bandwidth for all time slots assigned to this port. The
available options are 56k or 64k. This selection is multiplied by the number of time slots
assigned to the port, to define the overall port speed. For example, if you choose 64k as the
port Rate and assign four time slots to that port, the overall port speed is 256 kbps.
Tx CLOCK
The Transmit Clock (Tx CLOCK) setting identifies the clock source for the SD (send data)
signal from the external CPE. The int (internal) setting requires an external DTE to
synchronize its transmitted data with the clock on the SCT leads. The ext (extended) setting
requires the DTE to synchronize its transmitted data with the clock on the SCTE leads.
Use ext with a long cable run to ensure the data and clock are in-phase when they arrive at the
system. The DTE must loop back the clock on the SCT leads to the SCTE leads.
If ext is selected but the system does not detect an incoming clock on the SCTE leads, the HSU
Card automatically generates an internal clock. If this clock is not synchronized with the
incoming data, reset the CLOCK PLRTY option to synchronize the clock and data. The Tx
CLOCK PLRTY option settings are described in the next paragraphs.