Delta Controls DZNR-768, Руководство по установке

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Diagnostics and troubleshooting
Page 20 of 28 DZNR-768 Revision 1.2 Installation Guide
Document Edition 1.5
Diagnostics and troubleshooting
Troubleshooting a large network is easier when the controllers are distributed over multiple
segments. In this way, a failure is restricted to a particular segment rather than appearing
across the entire network. The DZNR quickly shows the status of every device on every
segment. By observing deviations from a normal LED pattern, one can determine if the
network is performing optimally or whether a possible device or wiring problem may exist.
DZNR power-up sequence
After the DZNR first powers up, it goes through a brief self-initialization period. All the LED
indicators turn on for 5 seconds. During this period, the DZNR examines every device that is
properly communicating on the network and retains those addresses until it loses power or is
reset. If a device fails to communicate during the initialization period, it will not be recognized
by the DZNR and its LED remains off. However, any missing device can be checked against the
label as to ascertain whether it is present or missing.
Recommended diagnostic procedure
Most network faults are steady state. With the DZNR, you can quickly determine if a specific
problem is unique to a particular device and isolated to one segment. Steady state problems
include: failure of a device, duplicate address of two or more devices, or a break in the wiring.
Using a consistent and methodical approach, the following diagnostic procedure is
recommended:
1. Note the condition of the device status LEDs and compare them to the known devices
shown on the DZNR label
2. Analyze the status of each segment Err LED
3. Check the state of the TX and RX LEDs on each segment
The following table describes the most common network problems and their associated LED
indications. Note the condition of the normal network. The goal of any troubleshooting exercise
is to restore the network is to its normal level of functionality.