Distech Controls ECLYPSE APEX, Руководство пользователя

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123 ECLYPSE APEX
For ECB-PTU Series Line-Powered Controllers:
The data bus’ cable shields must be twisted together and connected to the COM terminal at each
ECB-PTU Line-Powered Controller. Keep the cable shield connections short and take steps at each
device to isolate the cable shield from touching any metal surface by wrapping them with electrical
tape, for example. Note that for ECB-PTU Line-Powered Controllers, the data bus’ cable shield pro-
vides the ground reference for the data bus (see
BACnet MS/TP is a Three-Wire Data Bus ). If the con-
troller is at the end of the BACnet MS/TP data bus, simply connect the data bus shield to the COM ter-
minal.
ECLYPSE Series Controller:
The data bus’ cable shields must be twisted together and connected to the S terminal at each
ECLYPSE Series Controller. Keep the cable shield connections short and take steps at each device to
isolate the cable shield from touching any metal surface by wrapping them with electrical tape, for ex-
ample. Note that for ECLYPSE Series Controllers, the data bus’ cable shield provides the ground ref-
erence for the data bus (see
BACnet MS/TP is a Three-Wire Data Bus ). If the controller is at the end of
the BACnet MS/TP data bus, simply connect the data bus shield to the S terminal.
The APEX controller has a GND terminal that must be connected to 24V COM (2-wire) or directly to
ground (3-wire) to ensure a functional RS485 data bus (see
Power Wiring with APEX )
Grounding the shield of a data bus segment in more than one place will more than likely reduce shielding
effectiveness.
ECB 24V-Powered Controller Data Bus Shield Grounding Requirements
The shield on each data bus segment must be connected to the electrical system ground at one point
only, for example, at the ECLYPSE Series Controller, as shown in the figures below.
Typical BACnet 24VAC-
Powered Controller
Data Bus Shield:
Isolate with
electrical tape
Typical BACnet 24VAC-
Powered Controller
Data Bus Shields: Twist
together and Isolate
with electrical tape
Typical BACnet 24VAC-
Powered Controller
Data Bus Shields: Twist
together and Isolate
with electrical tape
Typical BACnet 24VAC-
Powered Controller
Data Bus: Shielded Twisted Pair Cable
N
ET
+
N
ET
-
N
ET
+
N
ET
-
N
ET
+
N
ET
-
N
ET
+
N
ET
-
Data Bus Shield:
Connect to the ‘S’
terminal
Electrical
System
Ground
The shield of the data bus must be connected to
the electrical system ground at one point only –
usually at the Building Controller, when present
RS-485
- +
S
ECLYPSE
Figure 95: Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment with an ECY
Series Controller located at the End of the Data Bus
Typical BACnet 24VAC-
Powered Controller
Data Bus Shield:
Isolate with
electrical tape
Data Bus Shields:
Twist together
and isolate with
electrical tape
Typical BACnet 24VAC-
Powered Controller
Typical BACnet 24VAC-
Powered Controller
Data Bus: Shielded Twisted Pair Cable
N
ET
+
N
ET
-
N
ET
+
N
ET
-
N
ET
+
N
ET
-
Typical BACnet 24VAC-
Powered Controller
N
ET
+
N
ET
-
Data Bus Shield:
Isolate with
electrical tape
Data Bus Shields:
Connect to the ‘S’
terminal
Electrical
System
Ground
The shield of the data bus must be connected to
the electrical system ground at one point only –
usually at the Building Controller, when present
Data Bus Shields: Twist
together and Isolate
with electrical tape
RS-485
- +
S
ECLYPSE
Figure 96: Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment with an ECY
Series Controller located in the Middle of the Data Bus
BACnet MS/TP Communication Data Bus Fundamentals