4230-mmm & 4230-mmx.ib.rev4.doc
Page 3 of 17
17/10/2007
IRT Eurocard
Types MMM-4230 & MMX-4230
4 Channel ASI to G.703 Multiplexer/De-Multiplexer
General Description
The MMM-4230 and MMX-4230 are part of a family of data transcoders for converting between the commonly
used MPEG2 Transport Stream formats for video distribution in the broadcast industry.
With the MMM-4230 up to four ASI and one RS422 data signals can be multiplexed together and converted into a
framed or unframed DS3 signal for transmission down a single 45 Mb/s G.703 line.
The MMX-4230 converts and demultiplexes the 45 Mb/s G.703 signal back into the original four ASI signals (at
their original rates) and the RS422 data signal.
An on board switch on the MMM-4230 sets the maximum data rates for each ASI input allowing the efficient use of
the available bandwidth and for protection against overuse of the bandwidth by the other channels. Total maximum
data rate up to 43.5 Mb/s is allowed. Temporary packet stuffing is used to automatically bring the rate up to
45 Mb/s.
Inputs are automatically equalised for lengths of up to 300m of Belden 8281 or equivalent cable.
RS422 9600 Baud uni-directional data may also be sent on the same link.
Front panel indication and relay alarm on the MMM-4230 transmitter shows if there is an input data rate violation.
Corresponding alarm on the MMX-4230 receiver shows a loss of G.703 input.
An optional Simple Network Management Protocol (SNMP) plug-in module is available for remote monitoring of
input and output status, control and alarm states.
The MMM-4230 and MMX-4230 are designed to fit IRT’s standard Eurocard frames as well as IRT’s 4000 series
frame for use with IRT’s SNMP system and may be used alongside any other of IRT’s analogue or digital
Eurocards.
Note:
Also available in a 34 Mb/s G.703 version. See “Configuration - switch settings” section for configuration
table.
Standard features:
•
Up to 4 ASI and 1 Data stream on one 45 Mb/s G.703 link
•
Input rate stuffing to 45 Mb/s G.703 rate
•
Selectable input maximum data rates
•
Automatic Input equalisation up to 300m
•
Suitable for Single Frequency Network (SFN) use
•
Optional SNMP plug-in monitoring and control module
•
Eurocard format
MMM-4230
MMX-4230
Mux
&
Signal
Processing
ASI-1
Input
G.703
Output
ASI-2
Input
ASI-3
Input
DATA
Input
Processing
&
De-Mux
ASI-1
Output
G.703
Input
ASI-2
Output
ASI-3
Output
DATA
Output
ASI-4
Output
ASI-4
Input
SNMP
SNMP
