Westermo MM-61 - Manual (Page 5)

Attenuation in fibre cable
The values below can differ depending on quality and manufacturer of the fibre optic cable.
Fibre Attenuation at 820 nm
50/125 µm 3,0 dB/km
62.5/125 µm 3,5 dB/km
200 PCS 4,0 dB/km
Typical attenuation in connectors Typical attenuation in splice
0.2-0.4 dB Fusion 0.1 dB
Mechanical 0.2 dB
Connections MM-61
(25 pole D-sub female or 25 pole D-sub male)
Direction 1) Connection no. Description
DCE DTE
I O 2 TD1
O I 3 RD1
I O 4 TD2
O I 5 RD2
- 7 SG/Signal Ground
O I 8 RD3
I O 20 TD3
O I 9 RD4
I O 10 TD4
1) I = Input O = Output on MM-61. TD= Transmitted Data and RD= Received Data.
The 4 channels can also be used for transmitting handshake signals like RTS,CTS,DTR
or signals for synchronous transmission Transmit Clock ( pin 15 )( DCE ), Receive Clock ( pin 17 )
and External Clock ( pin 24 )( DTE ).
Line connection
M M -6 1
T X
C h . 1
R X
C h . 1
M M -6 1
T X
R X