PowerWave 2 Bus System BCMS Setup and Operation
Cntl Nr: PM375107-002
12
together. However, the total number of devices in the chain
—
power feeds and Tap Off boxes
—
cannot
exceed the Modbus limit of 247 total devices.
An Accumulator has two (2) RS 485 connectors for Modbus RTU device chaining (see Figure 2, Steps 4-5
and Figure 3). For chaining Accumulators:
•
J5
is the upstream connection to the next Accumulator PCB or to the upstream Modbus master
device.
•
J6
is the downstream connection to the previous PCB in the chain.
Figure 3 Daisy-chaining Accumulators
2.3.2
Daisy-chaining Power Feeds using Modbus TCP/IP
You can daisy-chain up to (32) power feeds with Modbus TCP/IP using the (2) Modbus TCP/IP Ethernet
ports on the Comm Box (see Figure 1).
2.4
Tap Off Box Connections
If you have selected Tap Off Box monitoring, then each Bus Rail, Elbow, and Tee in the bus run will have a
Communications Cable installed. The Communications Cable carries 24VDC and Modbus communication
for Tap Off Box BCMS (see Figure 4).
See
PowerWave 2
™ Bus System
, 250A-800A, Installation and Operation, PM375106
for instructions on
inserting Tap Off Boxes into a Bus Rail. To connect the Tap Off Box to the Communications Cable, connect
the monitoring cable from the left side of the Tap Off Box to the Bus Rail (see Figure 4). The connection to
the Communications Cable is the same for all generations of Tap Off Boxes. However, the Quick Connect
Tap Off Box has a USB cable that must first be connected to an adapter (Figure 5).
IMPORTANT! Tap Off Boxes should be inserted in the bus run during setup to correctly identify
and address the units. Alternatively, you can install Tap Off Boxes, but delay connecting the Tap
Off Box Communications Cable to the Bus Rail until setup.
See Chapter 3
,
“
BCMS Setup: Accumulator
Application,
”
in this manual.
. . . .
J5
J6
Accumulator 32
J5
J6
Accumulator 1
J5
J6
Accumulator 2
To Modbus Master Device:
BMS, DCIM system,
WaveStar BCMS Hub, or
PowerWave 2 7-in Local Display
Up to (32) Accumulators (or power feeds)
can be chained together if the Modbus total
device limit (247) is not exceeded.
If the 7" Local Display is used, at most (6)
Accumulators (or power feeds) can be
chained together.
