Specifications
Table Of Contents
- Introduction
- Installation Procedures
- Commissioning Procedures
- Troubleshooting Procedures
- Overview
- Checking for Good Wire Runs
- Checking for Proper Termination
- Checking the End-of-Line Device Settings
- Checking for Proper Channel Selection
- Checking the N2 Device
- Checking the Number of Defined N2€Devices
- Checking the Length of N2€Bus
- Checking for “T” or “Y” Connections
- Checking for a Ground Loop
- Checking the Repeater
- Checking the Surge Protector
- Checking the Communication Terminal Board
- Checking Communication Faults
- Ordering Instructions
Network Communications—N2 Communications Bus
23
Figure 9 shows a branched N2 Fiber layout. Any path from the NCM to an
N2 device cannot go through more than two pairs of 2110 modems
(i.e., cascaded modems). This is because the 2110 modems delay the
N2 Bus signal, and the N2 can only compensate for two of these delays;
therefore, up to two pairs of 2110 modems can be cascaded in series. This
configuration is shown in the middle of Figure 9.
TBC
NCU
N
C
M
To Local
N2 Devices
To R emot e
N2 Devices
N2 Bus
N2 Bus
EOL=Out
EOL=In
N2FIBER2
To R emot e
N2 Devices
EOL=Out
EOL=In
NCM's
EOL=In
N2 Bus
EOL=In
EOL=In
N2 Bus
EOL=Out
EOL=In
To R emot e
N2 Devices
Notes: Only two pairs of fiber modems
can be cascaded.
For end-of-line terminations,
see the
Setting Terminations
section of this document.
To Local
N2 Devices
Fiber
Cable
Fiber
Cable
Fiber
Cable
Fiber
Cable
S.I.Tech
2110
RT
S.I.Tech
2110
RT
S.I.Tech
2110
RT
S.I.Tech
2110
RT
R
S.I.Tech
2110
T
R
S.I.Tech
2110
T
R
S.I.Tech
2110
T
R
S.I.Tech
2110
T
Figure 9: N2 Bus Layout with Branched Fiber Modems