22
SHM-768K
Table 3-2. SHM-768K Strap Selection (continued).
Strap Identity Function
Possible
Factory
Settings
Setting
No. 6
Enables Remote loopback
EN
DTE
command from the DTE
DIS
DIS
Command
(via Pin 21) for EIA-530, or via
RLB
Pin H for V.35.
No. 7
When set to ON, the V.54 delay
ON
V.54 DLY
is activated, preventing multiple
OFF
OFF
loopback of tail-end circuits.
No. 8
Used only for X.21 interface.
EX. CK
X.21 EX. CK
When using an external clock,
INT
INT
set the jumper to EX. CK. In
other cases (internal or receive
clock), set to INT.
No. 9
In CONNECT position, signal
CONNECT
CONNECT
CHASSIS
ground is connected to chassis
DISCONN
GND
ground. In DISCONN position,
the signal ground is isolated
from the chassis ground.
NOTE
If the DTE does not provide the test pins for analog and remote loopback,
the “DTE command” jumper for ALB and RLB must always be set to DIS.
