Table of Contents
Advertisement
Troubleshooting Options
9. If you see errors and diagnostics, it is likely that there is an issue with the BACnet
10. Reconnect the link and move to the device that is half-way back toward the Tracer
11. Disconnect the wire leading to the outward part of the link (away from the Tracer
12. Repeat
Network Voltage Measurement
The general procedure is to measure the dc voltage across the plus (+) and minus (-) communication
terminals at any device on the network. With terminators, the normal operating range that provides
adequate communication is 0.3V to 0.5V. Less than 0.2V is inadequate.
Note: You can obtain this voltage measurement with all devices on the link powered up and running.
Table 8.
Characteristics associated with specific problems on the BACnet
Condition
Normal
®
Two powered Trane BACnet
terminators
®
One powered Trane BACnet
terminator
®
Two unpowered Trane BACnet
terminator
®
No Trane BACnet
terminators
Cut the minus (-) comm wire
Cut the plus (+) comm wire
Minus (-) comm wire grounded
Plus (+) wire grounded
Comm polarity reversed
Dead Short across the comm link
41
side of the broken link.
alligator clips from the USB Comm4 adapter to the plus (+) and minus (-) terminals on the device and
run a SerialSpy capture.
Step 4
and
Step 5
Vdc
(a)
Normal
Min = 0.33
Max = 0.60
Avg = 0.45
(b)
(refer to Note
)
Min = 0.35
Max = 0.60
Avg = 0.45
(b)
(refer to Note
)
Min = 0.003
Max = 0.45
Avg = 0.21
(b)
(refer to Note
)
Min = 1.1
Max = 2.2
Avg = 1.5
Normal
Min = 0.33
Max = 0.60
Avg = 0.45
(b)
(refer to Note
)
Normal
Min = 0.33
Max = 0.60
Avg = 0.45
(b)
(refer to Note
)
Min = 0.54
Max = 0.64
Avg = 0.58
(voltage range is very flat)
Min = –0.50
Max = 0.16
Avg = 0.20
(voltage goes negative)
0.60 V
(very steady, no
fluctuation)
0 V
until the problem is isolated.
LEDs
Normal
Tx = quick flash
Rx = almost solid on
Normal
Tx = quick flash
Rx = almost solid on
Normal
Tx = quick flash
Rx = almost solid on
Normal
Tx = quick flash
Rx = almost solid on
Normal
Tx = quick flash
Rx = almost solid on
Normal
Tx = quick flash
Rx = almost solid on
For units on the same transformer
Tx = quick flash
Rx = almost solid on
Other units are unaffected
Normal
Tx = quick flash
Rx = almost solid on
Tx = off
Rx = Weak flashing
Tx = weak solid on
Rx = off or very weak
®
®
®
MS/TP link
Serial Spy
Normal
Clean token pass
No (or few) blue diagnostics or errors
Normal
Clean token pass
No (or few) blue diagnostics or errors
Normal
Clean token pass
No (or few) blue diagnostics or errors
Normal
Clean token pass
No (or few) blue diagnostics or errors
Normal
Clean token pass
No (or few) blue diagnostics or errors
However, all units past the wire break stop
communicating — looks like two separate
links, each intact
Normal
Clean token pass
No (or few) blue diagnostics or errors
However, all units past the wire break stop
communicating — looks like two separate
links, each intact
All units sharing a transformer with grounded
units are comm down. The rest of the link is
normal.
Normal
Clean token pass
No (or few) blue diagnostics or errors
Junk during idle — framing errors
Junk during idle — framing errors
Bad header, fast scrolling
link on the inward
®
SC+.
SC+). Connect the
(c)
(c)
(c)
(c)
(c)
(c)
(c)
BAS-SVX51L-EN
Advertisement
Table of Contents
