Technical information

51
PVP250kW & PVP260kW Inverter
Installation & Operation Manual
Note: The Modbus master connections are not enabled at this time.
D. Connect a ground reference line to the terminal labeled “GND” on the Modbus slave
connector. The shield of a communications cable may be used for this reference as
long as the shield is connected to earth ground at one point only. It is recommended
that PV Powered devices have connected grounds when possible.
Note: Some Modbus devices do not have a shield or reference input. In these cases
the device most often uses the DC power supply (-) as the RS-485 reference. It
may be necessary to place an RS-485 isolator on these devices or power them
from a common DC supply that has its DC (-) referenced to earth ground at the
same point where the network cable shield is earthed.
Figure 5-3 Daisy Chain Layout for RS-485 Network
When multiple inverters or other Modbus slave devices are connected to a single Modbus
master device, the multiple devices need to be connected in a daisy chain as shown in
Figure 5-3.
Note: When multiple devices are wired to the network the network shield must
be terminated to earth ground at one point on the network typically at the
beginning or the end. For device connections the shield must be rewired to
provide a continuous shield and isolated from ground.