DNT-T221 (Rev 4.1) Installation Guide
Network Topology
1. BACstats Configured as MS/TP Subnet Devices
With V3.21 firmware or higher, one possible MS/TP network architecture has the MS/TP devices configured as
Subnet devices, which allows BACstats to reside on the MS/TP network with other Subnet devices. Note that
V3.21 requires a DCU, while V3.22 or higher may use any System Controller instead.
2. BACstats Configured as LINKnet Devices
The BACstat may reside on LINKnet instead of MS/TP. However, this requires a controller that supports a
LINKnet network for I/O expansion. The maximum LINKnet devices with or without I/O depends on the
controller. All built-in applications must be disabled, but the I/O may be muxed (with V3.22 or higher
firmware).
DCU/DSC
(System Device)
BACnet (MS/TP) - Level 3 Network (Subnet)
DAC
(Subnet
Device)
TRM
DAC
(Subnet
Device)
TRM
Level 4
Network
(LINKnet)
16x16 Controller
12x12 Controller
12x8 Controller
6x6 Controller
Room Controller
VAV/VVT Controller
Lighting Controller
BACstat I
BACstat II
(with or without I/O)
Input Field Modules
Subnet Devices
DSC-1616EX [DCU]
DSC-1616(H/E)
DSC-1212(H/E)
DSC-1280(H/E)
DSC-T305
System Devices
RS-485
NET1
NET2
NET1
NET2
RS-232
BACstat I
BACstat II
(with No I/O)
BACstat II
(with muxed I/O)
I/O Field Modules
LINKnet Devices
TRM
Level 4
Network
(LINKnet)
LINKnet Notes:
1. Ensure you use the recommended
balanced cable.
2. Ensure the cable is installed as a daisy-
chain from one device to the next. (1000'
or 300m maximum).
3. *Ensure you jumper select a MS/TP
termination resistor when you have more
than 1 or 2 devices.
4. Depending on the controller, up to 12
devices are supported on a LINKnet
network, with limitations on how many of
these may have I/O. (Refer to the
Technical Reference Manual.)
ORCAview
OWS
DFM
Ethernet Note:
If the DCU or DSC has Ethernet capability, it may exist on an
Ethernet network with other controllers in the same building, on which
the ORCAview OWS could reside as well (instead of PTP).
PTP
MS/TP Notes:
1. Ensure you use the recommended balanced cable.
2. Ensure the cable is installed as a daisy-chain from one
device to the next (4,000' or 1220m maximum).
3. *Ensure you jumper select a termination resistor on each
end of each MS/TP network segment.
4. The maximum nodes per MS/TP network is 50 without a
repeater or up to 99 with at least one repeater (RPT-768).
Network Diagram
(with V3.22 Firmware)
* Note 3
Page 8 of 10
Document Edition 1.8
