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DNT2400 - 08/18/09
3.7 Interfacing to 5 V Logic Systems
All logic signals including the serial ports on the DNT2400 are 3.3 V signals. To interface to 5 V signals,
the resistor divider network shown in Figure 3.5.1 below must be placed between the 5 V signal outputs
and the DNT2400 signal inputs. The output voltage swing of the DNT2400 3.3 V signals is sufficient to
drive 5 V logic inputs.
5 V
L o g i c
D N T 5 0 0
2 . 2 K
4 . 3 K
Figure 3.7.1
3.8 Power-On Reset Requirements
When applying power to the DNT2400, the /RESET pin should be held low until the power supply voltage
reaches 3.3 volts for 100 milliseconds.
3.9 Mounting and Enclosures
DNT2400C radio modules are mounted by reflow soldering them to a host circuit board. DNT2400P
modules are mounted by plugging their pins into a set of mating connectors on the host circuit board.
Refer to Section 8.3 and/or the DNT2400 Data Sheet for DNT2400P connector details.
DNT2400 enclosures must be made of plastics or other materials with low RF attenuation to avoid com-
promising antenna performance where antennas are internal to the enclosure. Metal enclosures are not
suitable for use with internal antennas as they will block antenna radiation and reception. Outdoor enclo-
sures must be water tight, such as a NEMA 4X enclosure.
3.10 Labeling and Notices
DNT2400 FCC Certification - The DNT2400 hardware has been certified for operation under FCC Part 15
Rules, Section 15.247.
DNT2400 FCC Notice - This device complies with Part 15 of the FCC rules. Operation is subject to the
following two conditions: (1) this device may not cause harmful interference, and (2) this device must
accept any interference received, including interference that may cause undesired operation.
DNT2400 FCC Label - A clearly visible label is required on the outside of the user’s (OEM) enclosure
stating ”Contains FCC ID: HSW-DNT2400.”
WARNING: This device operates under Part 15 of the FCC rules. Any modification to this device, not
expressly authorized by RFM, Inc., may void the user’s authority to operate this device.
DNT2400
