VIPA System 200V IM Series, Manual

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Manual VIPA System 200V
Chapter 3 Profibus DP
HB97E - IM - Rev. 06/29 3-81
The fiber optic cable/optical waveguide (FO) transfers signals by means of
electromagnetic waves at optical frequencies. Total reflection will occur at
the point where the coating of the fiber optic cable meets the core since the
refractive index of this material is lower than that of the core. This total
reflection prevents the ray of light escaping from the fiber optic conductor
and it will therefore travel to the end of the fiber optic cable.
The FO cable is provided with a protective coating.
The following diagram shows the Structure of a fiber optic cable:
The fiber optic system employs pulses of monochromatic light at a
wavelength of 650nm. If the fiber optic cable is installed in accordance with
the manufacturers guidelines, it is not susceptible to external electrical
interference. Fiber optic systems have a linear structure. Each device
requires two lines, a transmit and a receive line (dual core). It is not
necessary to provide a terminator at the last device.
The Profibus FO network supports a maximum of 126 devices (including
the master). The maximum distance between two devices is limited to 50m.
•
wide bandwidth
•
low attenuation
•
no cross talk between cores
•
immunity to external electrical interference
•
no potential difference
•
lightning protection
•
may be installed in explosive environments
•
low weight and higher flexibility
•
corrosion resistant
•
safety from eavesdropping attempts
VIPA recommends to use FO connector and cable supplied by Hewlett
Packard (HP):
HP order no.: FO cable
HFBR-RUS500, HFBR-RUD500, HFBR-EUS500, HFBR-EUD500
HP order no.: FO connector
With crimp-type assembly: HFBR-4506 (grey), HFBR-4506B (black)
Without crimp-type assembly: HFBR-4531
For more see following page.
Profibus with
FO link
Advantages of FO
over copper
cables
FO cable
FO connector
1
2
3
4
[1] Fiber coating
[2] Protective cover
[3] Fiber core
[4] Ray of light