ROTRONIC HygroLog HL-NT - Manual (Page 39)

IN-E-HL-NT-V2_12
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroLog HL-NT data logger:
instruction manual Instruction Manual
Document Type
Page 39 of 48
Document title
© 2009-2012; Rotronic AG IN-E-HL-NT-V2_12
Example: HygroLog HL-NT and docking station with USB port
The number of HygroLog HL-NT and docking station with USB port that can be directly connected
to a PC depends on the number of USB ports available on the PC.
IMPORTANT:
- If you change an instrument from master to slave, be sure to change the RS address of the
instrument to 00 before establishing the RS-485 connection. Not doing so may prevent HW4
from detecting the instrument. After detecting the instrument, HW4 will automatically change
the RS address to 02 or higher. Please note that HW4 may eventually change the address of
any master with address 00.
- All devices connected to the same RS-485 multi-drop should use the same Baud rate and the
same communications protocol.
- Docking stations with Ethernet (TCP/IP) interface: please note that the Baud rate of the
HygroLog HL-NT and the Baud rate of the docking station internal Ethernet module should be
set to the same value
The RS485 wiring can be done with a twisted pair (2-wire, telephone type) and wall mounted
RJ45 receptacles (see Electrical installation guidelines in this manual). Be sure to observe the
polarity for each connection. Using 4-wire cable, offers the option of powering all devices in the
multi-drop from a single DC voltage source.
9.4 General wiring guidelines
Power supply wiring
Heavy machinery and instrumentation should not share the same power supply wiring. If this
cannot be avoided, noise filters and surge protectors should be used. Most UPS devices have
those features already integrated.
General guidelines for signal cables
The following guidelines are derived from European Standard EN 50170 for the transmission of
signals by copper wires. When planning an installation, the rules provided by EN 50170 should be
RS485: 2 wires
PC (HW4)
USB port Master
Address 1 Address 2 Address 64
NT
USB
RS485 RS485 RS485
Multi-drop: up to 1000m (3300 ft)
Slave
Slave