Cisco 6200 - Manual (Page 15)

78-5296-02 10/02/98 Hardware Description
1
Cisco 6200 User Guide 1-15
The upstream data transfer unit receives data via a 16-bit parallel input from the internal bus on the
node’s backplane. ATM cells are received from a subscriber line card (SLC) channel only after that
channel has won access to the upstream data bus from the other contending line channels. The
upstream data transfer unit monitors the contention bus to direct inbound data to the optical interface.
The downstream data transfer unit inserts data onto the bus. This circuit inserts idle cells when a full
data cell is not yet ready for transmission.
1.3.5 NTC STM-1: Physical Description
The NTC resides in slot 1 (the left-most slot as you face the front of the chassis). Each NTC STM-1
faceplate is marked NTC STM1-SM (single-mode) or NTC STM1-MM (multimode). The faceplates
(see Figure 1-8) include the fixtures discussed in the following paragraphs.
Trunk Port
The dual SC connectors (one for transmitting, one for receiving) for the Cisco 6200 network trunk
port are recessed into the NTC faceplate to prevent the cables from protruding too far outside the
faceplate.
Warning Class 1 laser product.
Warning Because invisible laser radiation may be emitted from the aperture of the port when no cable is
connected, avoid exposure to laser radiation and do not stare into open apertures.
The fiber optic communication channels in the single-mode trunk card (NTC STM1-SM) operate
with laser energy, which can be harmful, especially to the eyes. During normal operation this energy
is confined to the cable and presents no danger. To avoid injury when you are connecting or
disconnecting optical channels, observe these precautions:
•
Always disconnect the card from the backplane before connecting or disconnecting optical
cables.
•
Always keep the protective cap on the optic connector when the connector is not in use.
•
Never look into an optical cable or connector.
Reset Switch
The reset switch is recessed behind the faceplate to avoid accidental disturbance. It is not for
customer use.