1. Summarize
Model 268 is a sort of more function and economy RS-485/RS-422 interface optic fiber
MODEM. It is the best choice to connect RTU to HOST or SCADA controller. It used
Optic fiber as transfer medium, increase the transfer function of system. Communication equipment abstain menace effective to lightning strike, surge, electromagnetism disturb under the scurviness environment.
2.Function and Characteristic
a) Support RS-485/RS-422 interface
b) Asynchronous, point to point, rate up to 120Kbps
c) Support 5V DC power input,
d) 1500W surge protection, 15KV static protection
e) RS-485/422 port support 32 node ( can choice
handtailor 128 Node)
f) Working wavelength: 850nm(multi-mode)
1310nm(single mode)
g) Auto test signal rate, zero delay auto transmit.
3. Performance guideline
Interface: support EIA RS- 485,RS- 422 standard
Rate: 0-120Kbps
Transmit distance: RS485/422 port 1200m, optical port multi-mode 2KM, single-mode20KM
Working environment: -25℃ to 70℃
4. Appearance guideline
Interface type: 5 bit terminal block(RS-485/422), multi-mode choice ST/
SC/FC interface, single-mode choice FC/SC/ST interface
L*W*H: 100mm*69mm*22mm
Shell: Iron


Colour: White
Weight: 230g
5. Pin define
RS- 422 port
T+ —— RS-422 Send +
T- —— RS-422 Send -
R+ —— RS-422 Received +
R- —— RS-422 Received -
GND —— Ground
RS-485 port
D+ —— RS-485 +
D- —— RS-485 –
GND —— Ground
Optical fiber interface
IN —— Optical fiber input
OUT —— Optical fiber output
6. Indicator light explain
Power: Power indication
RxD: Optical fiber interface receive indication
TxD: Optical fiber interface send indication