Digital Media 900TL User Manual

PK–02586–IL

1 ) Power LED. Lights when the MAU has power.

2 ) Module OK LED. Lights when the MAU passes its 

self-test. If the MAU fails its self-test, the OK LED is
off.

3 ) Ring A/B LEDs. In a hub, either the A LED or the B

LED is on to show the ring. In a standalone MAU, 
both Ring LEDs are always off.

4 ) Speed LEDs. Either the 16 LED or the 4 LED is on

to show the ring speed. 

5 ) Eight Lobe LEDs. Lights when a station has access

to the network.

6 ) Eight Lobe Connectors. Connects a station to the

network. The MAU connects up to eight stations with
shielded or unshielded 100-ohm cable, and 150-ohm
IBM Type 1 data cable using an impedence matching
transformer cable (Digital part number BN26T-03).

7 ) Reset Switch. Resets the MAU to factory defaults.

To reset: while turning on the power, press the reset
switch with a pen or screwdriver.

Notes:
The DECmau 900TL has speed detect, which 
ensures the integrity of the network. At startup,  a
MAU determines the ring speed based on the
speed settings of the majority of the stations on the
ring and the Ring Out port. In a hub, the MAU then
connects to the appropriate ring in the hub. After
startup, speed detect prevents stations with the
wrong speed setting from connecting to the net-
work.

Network management can override any of the
MAU’s factory default settings.

LKG-8145-93I

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