Distech Controls ECL/ECB-PTU Series User Manual page 116

Table 31: Verify that the Following Recommendations have been Carried Out Before Calling Technical Support
Recommendation
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)
114
Description
Ensure that the polarity of all data bus wiring is consistent throughout the network. See
net MS/TP data bus is polarity sensitive
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 maxi-
mum MAC Address in the ECY Series 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 unim-
portant: 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
24VAC-Powered Controllers on page 171.
on page 146.
Power Supply Requirements for
BAC-
Network Guide