ROTRONIC HC2 - Manual (Page 13)

E-M-HC2-accessories_24
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
Accessories and Parts
for probes, indicators and transmitters Instruction Manual
Document Type
Page 13 of 23
Document title
© 2009-2010; Rotronic AG E-M-HC2-accessories_23
7.1.1 Powering the networked devices from the RS-485 main data line
Depending on the model, the devices connected to a RS-485 network can be powered from the main data line
as opposed to each device being powered separately. Please check the instruction manual of each device
.
The AC3010 offers the following options to power devices from the main data line:
a) Power directly from the USB port
Cable AC3010 has two wires (V+ and GND) that can be used to power the networked devices directly from
the USB port (5 VDC, 100 mA). In addition to the limit of 100 mA, the length of the main data line should not
exceed 100 m / 330 Ft.
b) Power from a separate voltage source
When the networked devices are not powered from the USB port, the length of the main data line can be up to
1000 m / 3300 Ft.
Addr. 1 240
Ω
240
Ω
V + GND
Cable AC3010
Master Substitute
Does not have an
address
USB port (PC)
RS-485 Main Data Line (max. 1000 m / 3300 Ft)
Addr. n
TX- / RX-
TX+ / RX+
Separate
Voltage
Source
Addr. 1 240
Ω
240
Ω
V +
GND
Cable AC3010
Master Substitute
Does not have an
address
USB port (PC)
RS-485 Main Data Line (max. 100 m / 330 Ft)
Addr. n
TX- / RX-
TX+ / RX+