User Manual

3
Built-in RS-485 ADDC
TM
Intelligence
ADDC™ (Automatic Data Direction Control), a Moxa leading technology,
uses a clever hardware solution to take care of the RS-485 data flow control
problem. ADDC™ is a hardware data flow solution that automatically senses
and controls data direction, making the handshaking signal method
unnecessary.
Isolation
Moxa’s electrical isolation technology uses two photo couplers to create a
gap in each electrical signal. One photo coupler transforms the electrical
signal into a light signal, which is transmitted across a small gap, and then
the other photo coupler transforms the light signal back into an electrical
signal. In this way, the two electrical circuits are completely isolated from
each other, limiting the damage that could otherwise be caused by ground
loops in the electrical signal.
Reverse Power Protection
The Reverse Power Protection feature provides extra protection against
accidentally connecting the power cables to the wrong terminal. The
converter is designed to automatically detect which power wire is positive
and which is negative, and then adjust the power supply accordingly.
DIP Switch Selectable Terminator
For many products of this type, the termination resistor is set by a jumper
located inside the product’s casing, so that the user must open the casing to
disable or change the resistor’s strength. Moxa offers a better solution. The
TCC-120/120I’s terminator is set with a DIP switch located on the outside of
the converter’s casing.
Auto Baudrate Detection
The TCC-120/120I incorporates a method for automatically detecting the
serial signal’s baudrate by hardware. This is an extremely convenient
feature for the user. Even if a device’s baudrate changes, the signal will still
be transmitted through the RS-422/485 repeater without any problems.