TC Communications TC8614 User Manual page 19

Chapter 2 Installation
2.7.2.1 Rear Panel DIP Switch Functions
The DIP switch functions on the TC8614 are described below. To activate the
function, set the appropriate switch to the "On" (Down) position.
• LOCLB: Local Loopback. This switch (SW1) initiates the Local Loopback
function. The analog signals are received on the "RX Data" pins and looped
back to the "TX Data" pins for diagnostic testing.
• RMTLB: Remote Loopback. This switch (SW2) initiates the Remote
Loopback function. Enabling this switch on the local unit triggers the remote
loopback function on the remote unit.
• INT CLK: Internal Clock. This switch (SW3) is used to setup the T1 timing
mode. "On" for internal timing mode. "Off " for RX loop timing mode.
• B8ZS /HDB3: This switch (SW4) is used to setup the T1/E1 Line Code. "On"
for B8ZS(T1) or HDB3(E1). "Off" for AMI.
• DIS ALM: This switch (SW5) is used to disable the audio buzzer and dry
contact alarm relay. "On" (Down) position disables the buzzer and relay. "Off"
enables the buzzer and relay. "DIS ALM" dip switch should be in "Off" under
normal condition.
• L1, L2, L3: These switches (SW6, SW7, & SW8) are used to set the T1/E1
crossconnect distance (copper line build-out/impedance).
For example, in a T1/E1 application, this is the length of twisted pair cable
connecting the TC8614 to the user's equipment, which may be a CSU or DSU. See
Table 2-1 and Table 2-2 below.
Table 2-1: Copper Line Length Setup Table
T1 Settings
L1
Up
Down
Up
Down
Up
TC8614 Rev 1.4 User Manual
L2 L3
Up Up
Up Up
Down Up
Down Up
Up Down
Application Line Length
DSX-1 (0 to 133 feet) / 0 dB CSU
DSX-1 (134 to 266 feet)
DSX-1 (267 to 399 feet)
DSX-1 (400 to 533 feet)
DSX-1 (534 to 655 feet)
System Configuration
2-5