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CNT-SVX07D-EN
Status indicators for operation and communication
The yellow (communications) LED on the Tracer ZN521 controller (see Figure 19 on page 43)
indicate the controller’s communication status (see
Diagnostics
Diagnostics are informational messages that indicate the operational status of the controller. In
response to most diagnostics, the controller attempts to protect the equipment by enabling or
disabling, or opening or closing, specific outputs. Other diagnostics provide information about the
status of the controller, but have no effect on outputs. Diagnostics are reported in the order in which
they occur. Multiple diagnostics can be present simultaneously. Diagnostic messages are viewed
using the Rover service tool or through a BAS.
Types of diagnostics
Diagnostics are categorized according to the type of clearing method each uses and the type of
information each provides.
The four categories are:
•
Manual (latching)
•
Automatic (nonlatching)
•
Smart reset
•
Informational
Note:
Clearing diagnostics refers to deleting diagnostics from the software; it does not affect the
problem that generated the message. For help with diagnosing a problem, see
.
Manual (latching) diagnostics
Manual diagnostics (also referred to as
latching
) cause the unit to shut down. Manual diagnostics
can be cleared from the controller in one of the following ways:
•
By using the Rover service tool (see “Resetting a diagnostic” in EMTX-SVX01A-EN,
Rover
Installation/Operation/and Programming
guide)
.
•
Through a building automation system (see product literature)
•
By initiating a manual output test at the controller (see “Manual output test” on page 43)
•
By cycling power to the controller. When the 24 Vac power to the controller is cycled off and then
on again, a power-up sequence occurs.
•
By turning the zone sensor fan switch to
OFF
and then back to any other setting. (This feature
will be available beginning with controller software version 2.10.)
Automatic (nonlatching) diagnostics
Automatic diagnostics clear automatically when the problem that generated the diagnostic is
solved.
Table 15. Yellow LED: Communications indicator
LED activity
Explanation
LED is off continuously
The controller is not detecting any
communication (normal for stand-alone
applications).
LED blinks.
The controller detects communication (normal
for communicating applications, including
data sharing).
LED is on continuously.
Problem with communication link wiring
(possible need for termination resistor), or
controller failure (caused by power surge,
lightning strike, etc.)
Summary of Contents for Tracer ZN521
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