Acuity Controls nLight ECLYPSE User Manual page 117

Symptom
Hardware input is not
reading the correct value
Hardware output is not
operating correctly
Table 15: Troubleshooting Controller Symptoms
Action
Properly terminate the BACnet MS/TP data bus
Avoid duplicate MAC Addresses
All devices must be set to the same baud rate
The data bus is polarity sensitive
Do not overload the data bus with Change of
Value (COV) reporting
Do not leave address holes in the device's MAC
Address range
Only daisy-chained devices are acceptable
Connect no more than five devices to a power
supply transformer (for 24V controllers)
Table 16: Verify that the Following Recommendations have been Carried Out Before Calling Technical Support
nLight ECLYPSE
Possible Cause Solution
Number of controllers on
network segment exceeded
Max Master parameter
Input wiring problem
Open circuit or short circuit
Configuration problem
Over-voltage or over-
current at an input
Fuse has blown (Auto reset
fuse, for 24V controllers)
Output wiring problem
Configuration problem
0-10V output, 24VAC
powered actuator is not
moving
Recommendation
EOL terminations must be enabled / installed at either end of the data bus only. See
Terminations.
Verify that no device has a duplicate MAC Address by checking the MAC Address DIP switch settings
on all devices on the data bus, including segments connected by a repeater.
If necessary, isolate devices from the data bus to narrow-down the number of devices that may be at
fault.
When all devices are set to AUTO baud rate, at least one device must be set to a baud rate, usually
the data bus master. See
Baud Rate.
Ensure that the polarity of all data bus wiring is consistent throughout the network. See
Data Bus is Polarity
COV reports create the most traffic on the BACnet MS/TP data bus. Set the COV report rate to the
largest value that provides acceptable performance. Only map COV reports for values that are
necessary. For mapped analog points that are continuously changing, try increasing the COV
increment on these points or set the COV minimum send time flag to true to send the value at a
regular frequency.
Assign MAC Address to device starting at 3, up to 127. Do not skip addresses. Set the maximum
MAC Address in the Controller to the final MAC Address number actually installed.
NOTE: The physical sequence of the MAC Address of the devices on the data bus is unimportant: For
example, the MAC Address of devices on the data bus can be 5, 7, 3, 4, 6, and 8.
Eliminate T-taps and star configurations. Use a router to connect a data bus spur.
BACnet MS/TP devices require good power quality. See
Powered
The number of controllers on a channel should never exceed 50. Use a router or a repeater:
See Data Bus Segment MAC Address Range for BACnet MS/TP
Configure the maximum number of master device on the MS/TP network in all devices to the
controller's highest MAC address used on the MS/TP trunk. See
Token-Passing Overview.
Check that the wiring is correct according to the module's hardware installation manual and
according to the peripheral device's manufacturer recommendations.
Using a voltmeter, check the voltage on the input terminal. For example, for a digital input, a
short circuit shows approximately 0V and an open circuit shows approximately 5V. Correct
wiring if at fault.
Using the controller configuration wizard, check the configuration of the input. Refer to the
controller's user guide for more information.
An over-voltage or over-current at one input can affect the reading of other inputs. Respect
the allowed voltage / current range limits of all inputs. Consult the appropriate datasheet for
controller input range limits.
Disconnect the power and outputs terminals. Then wait a few seconds to allow the auto-
reset fuse to cool down. Check the power supply and the output wiring. Reconnect the
power.
Check that the wiring is correct according to the module's hardware installation manual and
according to the peripheral device's manufacturer.
Check the configuration of the output with an HVAC programming tool. For example, is it
enabled?
Check the polarity of the 24VAC power supply connected to the actuator while connected to
the controller. Reverse the 24VAC wire if necessary.
Maximum Number of BACnet MS/TP Devices on a Data Bus Segment and
Sensitive.
Controllers.
ECLYPSE Controller Troubleshooting
Devices.
BACnet MS/TP Data Bus
When to Use EOL
Power Supply Requirements for 24VAC-
BACnet MS/TP
117