Setup and adjustments
Important:
Electrostatic discharge can damage
controller components. Use proper electrostatic
discharge precautions during installation, setup, and
servicing to avoid damaging the controller.
Configuring N2 communications
About this task:
N2-capable controllers support the full range of possible
N2 device addresses provided by the N2 protocol
standards: 1 to 254.
To configure a controller to communicate using the N2
protocol, complete the following steps:
1. Disconnect the 24 VAC supply from the controller.
2. Set the address switches to the N2 address that
you want to use. For details about setting a device
3. Reconnect the 24 VAC supply to the controller.
4. Using an SA bus connection, download the
controller application file configured for N2 to the
controller.
Switching the communications protocol
from N2 to MS/TP
About this task:
For N2 sites that are converting to BACnet MS/TP, you can
switch the communications protocol of N2-configured
MS/TP controllers back to BACnet MS/TP.
To switch the controller operating in N2 mode back into
BACnet MS/TP mode, complete the following steps:
1. Disconnect the 24 VAC supply from the controller.
2. Set the address switches to the BACnet MS/TP
address that you want to use. For details about
.
3. Reconnect the 24 VAC supply to the controller.
4. Using an SA bus connection, download the
controller application file configured for BACnet
MS/TP to the controller.
Setting the device address
About this task:
The VAV1717 and VAV1732 controllers are manager
devices on BACnet
®
MS/TP (SA or FC) buses. Before
operating controllers on a bus, you must set a valid and
unique device address for each controller on the bus.
You set the device address by setting the positions of the
switches on the device address DIP switch block at the top
of the controller, see
through 127 are the valid addresses for these controllers
on an MS/TP FC bus.
The DIP switch block has eight switches numbered 128,
64, 32, 16, 8, 4, 2, and 1. Switches 64 through 1 are the
device address switches. Switch 128 is OFF for all FC bus
applications. See the following figure for an example of a
DIP switch block set to 21 for a wired FC bus application.
Figure 11: Device address switches set to 21
Note:
Controllers ship with switch 128 ON and the
remaining address switches OFF. This renders the
controllers wired subordinate devices, which do
not interfere on MS/TP buses and do not interfere
with bus operation. Set a valid and unique device
address on the controller before applying power to
the controller on the bus.
Refer to the
MSTP Communications Bus Technical Bulletin
(LIT-12011034)
for more information on field controller
device addresses and how to set them on MS/TP Buses.
To set the device address on the controller, complete the
following steps:
1. Set all of the switches on the DIP switch block (128
through 1) to OFF.
2. Set one or more of the seven address switches (64
through 1) to ON, so that the sum of the switch
numbers set to ON equals the intended device
address. See Table 10 for valid controller addresses.
Set the highest number switch that is less than or
equal to the intended device address to ON. Then
continue setting lower numbered switches until the
total equals the intended address. For example, if
the intended device address is 21, set switch 16 to
ON first, then set switch 4 to ON, followed by switch
1 (16+4+1=21). See Figure 11.
Table 10: Valid device addresses
FC bus
communicati
on mode
Valid device address range
Wired MS/TP 4 to 127
Note:
Addresses 0 to 3 are reserved
and not for use on equipment
controllers.
Zigbee
wireless
4 to 127
Note:
Addresses 0 to 3 are reserved
and not for use on equipment
controllers.
N2
1 to 254
Note:
Addresses 0 and 255 are
reserved and not for use on
equipment controllers.
VAV1717 and VAV1732 VAV Controllers Installation Guide
15