MOST150 E-O Converter
DS60001342C
14
© 2015 - 2017 K2L GmbH & Co. KG
K2L - USER’S GUIDE
3.2 Physical Layer Conversion
The primary function of the MOST150 E-O Converter is network signal conversion between electrical
coaxial and optical physical layers. The MOST150 E-O Converter incorporates two PLLs to achieve
this conversion. The network frame rate of both electrical cPHY and optical physical layer networks is
48 kHz. One PLL receives the incoming cPHY network signal and retransmits it as the outgoing optical
physical layer network signal (Interconnect); the other PLL receives the incoming optical physical layer
network signal (Interconnect) and retransmits it as the outgoing electrical cPHY network signal. This
electrical cPHY to optical physical layer conversion is accomplished by re-clocking the MOST network
(data rate: 150 Mbit/s) signal while maintaining data integrity.
The optical physical layer signal is a pseudo MOST150 network interface that uses Small Form-factor
Pluggable (SFP) transceivers. Since the optical physical layer network produces no emissions and is
isolated electrically, it can be routed through the EMC chamber wall and connected to another
MOST150 E-O Converter, where it is converted back to an electrical cPHY network signal. The optical
physical layer interface consists of a 850 nm wavelength optical physical layer transceiver with a LC
duplex receptacle. This allows the signal to be transmitted over multi-mode, 50/125 µm glass optical
fiber cable for distances up to 40 m. The MOST150 E-O Converters can be integrated into larger
chambers without adding any significant delay to the network.
The incoming electrical cPHY (MOST) and optical physical layer (Interconnect) network signals are
checked for coding errors and network unlocks. Any time an electrical cPHY network error occurs, the
MOST LED shows an error (red, refer to
Section 4.1.2.2, "MOST," on page 16
). Any time an optical
physical layer network error occurs, the Interconnect LED shows an error (red, refer to
).