Lanex TM-78 Operating manual - page 20
10Base-T/100Base-TX/E1 converter
Operating Manual
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IOA78-1C 15 January 2005
4.6. Clock setup
Three variants of converter operation are possible. The converters may transmit data,
depending on conditions and capacity of the telecommunication network, in the following layouts:
• MASTER-MASTER
• MASTER-SLAVE
• SLAVE-SLAVE
The converter operates in MASTER mode when the clock source for data transmitted to
the E1/G.703 interface is the clock from internal quartz generator. In SLAVE mode, clock source
for data transmitted to the E1/G.703 interface is the clock retrieved from the opposite direction of
transmission.
In MASTER-MASTER mode, both converters work with their own internal clocks –
plesiochronous transmission. Possible work with PDH and SDH systems configured in
asynchronous mode.
In MASTER-SLAVE mode, the master works with internal clock and the slave works with
retrieved clock – synchronous transmission. Possible work with PDH and SDH systems
configured in asynchronous mode.
In SLAVE-SLAVE mode, both converters work with retrieved clocks – synchronous
transmission. This configuration is only possible if the converters are connected to SDH
telecommunication network and the network operates in synchronous mode. Work with PDH
systems is not possible.
4.7. Configuration of the E1 G.703 interface
The converter has the following E1 G.703 interface configuration functions:
• CRC option available only in framing mode on
o switching this option on enables achieving proper integration with equipment that
requires transmission of the remainder of CRC division in zero slot C1-C4 bits
o switching this option off results in setting C bits of the zero slot in ‘1’ position
• Framing
o switching this option on enables proper integration with equipment operating with
G.704 framed signal and allows selection of a block of slots for transmission. In
addition, this option enables communication with the remote device on the side of
the E1 interface.
o option off results in blocked selection of slots, surveillance slot and CRC setting.
When the framing option is off, E1 stream is transmitted transparently. Therefore,
data can be transmitted at full speed of 2048 kbit/s.
• Multiframe
o Switching this option on enables proper integration with operating equipment that
uses the sixteenth slot for signals transmission.
o In this option, the sixteenth slot may not be used for data transmission
• Choice of surveillance slot number, to be used for managing the remote device connected
on the side of the E1 interface, option available only if framing is on.