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
55
Base Frame
TBC801
tbcfuse
Leads from Continuity Tester or Ohmmeter
Figure 32: Checking Fuses on the
Communication Terminal Board
You can use an oscilloscope to pinpoint communication faults over the
N2 Bus. The procedure requires a 2-channel scope with an A minus B
function or an A plus B with B inverted function. Follow these steps:
1.
Plug the scope into a grounded electrical outlet.
2.
Set both channels to 2 volts per division. Both channels must have the
same gain or volts per division setting.
3.
With no signal applied, adjust each channel’s vertical position at the
same graticule on the screen (i.e., center screen).
4.
Select the Channel A minus B function. If your scope does not have
this function, select the Add function (Channel A Added to B then
Invert Channel B),
5.
Select the 0.5 mS horizontal range.
Checking
Communication
Faults