Hardware reference guide

Modbus Plus NOM
294
35013379 02 October 2007
Specifications The following table shows the specifications for the NOM25200 module.
Specifications
General Communication Ports
Optical Ports 2 (consisting of an optical receiver and transmitter)
Modbus Port 1 RJ45 (phone jack-type) connector
Transmission/Data Rate 1 Mbit/second for Modbus Plus with Bi-Phase S
encoded data
Optical Interface ST-Type connectors
Pulse Width Distortions and Jitter 5 ns or better
Wavelength 820 nm
Power Loss Budget (includes 3 dB
of system margins).
50/125 micron fiber - 6.5 dB
62.5/125 micron fiber - 11 dB
100/140 micron fiber - 16.5 dB
Maximum Distance for point-to-
point connection
2 km over 50 micron fiber
3 km over 62.5 micron fiber
3 km over 100 micron fiber
Maximum System Length in Self
Healing Ring Configuration
10 km over 62.5 micron fiber
Optical Transmitter Specifications
Optical Power (Measured with 1 m
test fiber)
-12.8 ... -19.8 dBm average power in 50/125 micron
fiber cable
-9.0 ... -16 dBm average power in 62.5/125 micron fiber
cable
-3,5 ... -10.5 dBm average power in 100/140 micron
fiber cable
Rise/Fall Time 20 ns or better
Silence (OFF leakage) -43 dBm
Optical Receiver Specifications
Receiver Sensitivity -30 dBm average power
Dynamic Range -20 dB
Detected Silence -36 dBm
Miscellaneous Specifications
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com