Optical Terminal Selection Criteria

Criteria for Selecting Optical Terminals
I. Optical Terminal Types: Analog Optical Terminal/[Digital Optical Terminal]( Single-mode/Multi-mode
II. Transmission Distance: Fiber cable length/Fiber cable link loss (very important)
III. Video:
　　Number of video channels: 1/2/4/8/16/32/48
　　Connection method: Direct connection/Video distributor/Video splitter/Character overlay/Others
　　Display method: Monitor/Large screen/TV/Others
IV. Data:
　　Number of data channels: 1/2/3/4
　　Data type: RS232/RS485/RS422/TTL/Others
　　Data direction: Reverse/Same direction/Bidirectional
　　Rate (bps): 2400/4800/9600
　　Data application: Control/Alarm/Cascade/Image/Traffic facilities
V. Audio:
　　Number of audio channels: 1/2/3/4
　　Audio type: Balanced/Unbalanced
　　Audio direction: Reverse/Same direction/Bidirectional
　　Audio application: Broadcast/Microphone/Intercom/Others
Notes on Fiber Cable Loss:
Before selecting an optical terminal, it is advisable to understand the fiber link loss. This is beneficial for subsequent project installation. Generally, after fiber link splicing is completed, a test report is generated recording all fiber link loss data. It can also be calculated using the following empirical formula:
　　Fiber link loss = Fiber cable length * Fiber cable transmission loss per kilometer + 3dB
　　The loss value for 850nm wavelength in fiber transmission is 3dB/km
　　The loss value for 1310nm wavelength in fiber transmission is 0.35dB/km
　　The loss value for 1550nm wavelength in fiber transmission is 0.25dB/km