Synway TEJ-1A/PCI, Hardware Manual, Page: 11 / 14

Synway Information Engineering Co., Ltd
2.4 System Requirements
Host System Requirements
CPU: 800MHz Intel® Pentium®III or above
Memory: 64M or more
HD: Depends on individual requirements
Supported Operating Systems
Linux: Debian, Fedora, Rad Hat
2.5 Hardware Installation
Note: Always turn off the power before installation!
Step 1: Configure the grounding jumper.
Disconnect all grounding jumpers in the use of 100 Ω T1, 110 Ω J1 or 120 Ω E1 balanced twisted-pair
cable.
In consideration of various line conditions, this series boards are equipped with two groups of
grounding jumpers on each channel which respectively control the groundings of the transmitting
and receiving ends. In case the 75
Ω E1 unbalanced coaxial cable is used, the grounding jumpers
at the receiving end should be disconnected while those at the transmitting end should be
short-circuited, provided that the PC is properly grounded. This configuration is the factory default
setting and applicable to most situations so that there is usually no need to change it. If it is difficult
to ground the local PC, you may short-circuit the on-board grounding jumper at the receiving end
and use the transmitting end at the opposite terminal for grounding. If the receiving end at the
opposite terminal is grounded (improper operation), the on-board grounding jumper at the
transmitting end must be disconnected. Refer to Table 2-2 for details.
Generally speaking, even in the case of proper grounding at both terminals, only the external layer
of the E1 coaxial cable at the transmitting end is allowed to be grounded. The grounding of both
transmitting and receiving ends may result in a current loop with ground wires, bringing instability
to signals. Therefore, such grounding must be strictly avoided.
Transmit
End
grounded grounded non-grounded non-grounded
Opposite
Terminal
Local
Terminal
Receive
End
non-grounded grounded non-grounded grounded
PC grounded
Transmit
End
short-circuited disconnected short-circuited disconnected
Synway TEJ Series Hardware Manual （ Version 1.0 ） Page 7