Patton electronic NetLink-E1 2715 - Manual (Page 6)

Switch SW2: CAS Multiframe
The Channel Associated Signaling (CAS) multiframe uses Timeslot 16
(TS16) to send multiframe (MF) alignment data. In CAS MF, a multi-
frame is defined as 16 frames, where a frame consists of 32 64kb/s
timeslots, numbered 0 to 31. TS16 of the first frame in the MF contains
the CAS MF alignment word in the upper four bits. The alignment word
is always 0000 (binary). The 2715 does not perform any signaling in
TS16 other than to insert the MF alignment word, in order to maintain
MF alignment. When CAS MF disabled, the unit transmits user data in
TS16; therefore, up to 31 channels are available for user data. When it
is enabled, TS16 is not available to the user. In this case, the user can
use up to 30 channels for data. CAS MF can be used with CRC-4 MF
or by itself. When enabled, both units must employ CAS MF; if one unit
is set for CAS MF, and the other is not, the one using CAS MF will
detect a loss of sync.
SW2 Option
Off Disabled
On Enabled
Switch SW3 & SW4: CRC-4 Multiframe/Clock mode
In framed mode, SW3 is used for CRC-4 MF. CRC-4 Multiframe uses
Time Slot zero to carry CRC-4 information. It operates independently of
CAS MF. When CRC-4 is enabled, the unit monitors the incoming data
stream for CRC-4 errors. It transmits CRC-4 error counts to the trans-
mitting unit. Excessive errors may cause loss of frame or loss of sync.
If CRC-4 MF is used, both units must be set for set for CRC-4 MF.
Otherwise, the one using CRC-4 MF will detect loss of sync.
In unframed mode, SW3 is used to along with SW4 to determine the
clock mode. In unframed mode, the model 2715 can be set to network,
internal or external clock mode. This is done by setting both SW3 and
SW4 to the on position.
In framed mode SW4 is used alone to determine the 2715 transmitter
timing. The 2715 can be set to Network or Internal clock.
The following charts represent both cases.
9
CLOCK MODES
Network Clock Transmitter timing is derived from the received line
signal.
Internal Clock Transmitter clock is derived from an internal clock
source.
External Clock Transmitter timing is derived from the local DTE
device. Valid only in unframed mode.
Note: When using the 2715 as a high-speed short range modem, one
unit of the link must be configured in either internal or external clock,
and the other end must be configured for network clock mode.
Switches SW5, SW6, SW7, and SW8
Use Switches SW5, SW6, SW7, and SW8 to set the DTE data rate.
SW5 SW6 SW7 SW8 Speed
Off Off Off Off Clear Channel (2.048Mbps)
On Off Off Off 64kbps
Off On Off Off 128kbps
On On Off Off 192kbps
Off Off On Off 256kbps
On Off On Off 384kbps
Off On On Off 512kbps
On On On Off 640kbps
Off Off Off On 768kbps
On Off Off On 1024kbps
Off On Off On 1280kbps
On On Off On 1536kbps
Off Off On On 1600kbps
On Off On On 1920kbps
Off On On On 1984kbps
On On On On invalid
10
MULTIFRAME(G.704)
SW3 CRC-4 MF SW4 Clock Mode
On On Off Network
Off Off On Internal
UNFRAMED (G.703)
SW3 SW4 Clock Mode
Off Off Network (Default)
Off On Internal
On On External
On Off Network