Thermokon FT-RDF18+ User manual

FT-RDF18+ RS485 Modbus
Room sensor temperature and humidity, flush mounting at ceiling
Thermokon Sensortechnik GmbH, Platanenweg 1, 35756 Mittenaar, Germany · tel: [phone] fax: -400 www.thermokon.com· [e-mail]
FT-RDF18+_RS485_Modbus_Datasheet_en.docx © 2022
Datasheet
Subject to technical alteration
Issue date: 12.05.2022 • A121
»APPLICATION
Ceiling sensor for unobtrusive humidity and temperature measurement in the ceiling area of room and office spaces. Designed for control and
monitoring applications.
»TYPES AVAILABLE
Ceiling sensor temperature + humidity – active BUS
•FT-RDF18+ RS485 Modbus
Ceiling sensor with display temperature + humidity – active BUS
•FT-RDF18+ LCD RS485 Modbus
»SECURITY ADVICE – CAUTION
The installation and assembly of electrical equipment should only be performed by authorized personnel.
The product should only be used
for the intended application. Unauthorised modifications are prohibited! The product must not
be used in relation with any equipment that in case of a failure may threaten, directly or indirectly, human health or life o
r result
in danger to human beings, animals or assets. Ensure all power is disconnected before installing. Do not connect to live/operating
equipment.
Please comply with
•Local laws, health & safety regulations, technical standards and regulations
•Condition of the device at the time of installation, to ensure safe installation
•This data sheet and installation manual
»PRODUCT TESTING AND CERTIFICATION
Declaration of conformity
The declaration of conformity of the products can be found on our website https://www.thermokon.de/

Page 2 / 4 Issue date: 12.05.2022
Thermokon Sensortechnik GmbH, Platanenweg 1, 35756 Mittenaar, Germany · tel: [phone] fax: -400 www.thermokon.com· [e-mail]
FT-RDF18+_RS485_Modbus_Datasheet_en.docx © 2022
»BUILD-UP OF SELF-HEATING BY ELECTRICAL DISSIPATIVE POWER
Sensors with electronic components always have a dissipative power, which affects the temperature measurement of the ambient air. The
dissipation in active temperature sensors shows a linear increase with rising operating voltage. This dissipative power has to be considered when
measuring temperature. In case of a fixed operating voltage (±0,2 V) this is normally done by adding or reducing a constant offset value.
Thermokon transducers can be operated with variable operating voltages. The transducers are set at the factory with a reference operating voltage
of 24 V =.
At this voltage, the expected measuring error of the output signal will be the least. Other operating voltages, can cause a measurement deviation
changing power loss of the sensor electronics.
A recalibration can be carried out directly on the unit or via a software variable (app or bus).
Remark: Occurring draught leads to a better carrying-off of dissipative power at the sensor. Thus temporally limited fluctuations might
occur upon temperature measurement.
»APPLICATION NOTICE FOR HUMIDITY SENSORS
For standard environmental conditions re-calibration is recommended once a year to maintain the specified accuracy. A re-calibration may be
required sooner than specified, or the sensor element may have to be exchanged when exposed to the following environmental conditions:
•Mechanical stress
•Contamination (dust / fingerprints e.g.)
•Abrasive chemicals
•Environmental influences (e.g. condensation on measuring element)
Re-calibration and deterioration of the humidity sensor due to environmental conditions are not subject of the general warranty.
Refrain from touching the sensitive humidity sensor/element. Touching the sensitive surface will void warranty.
»TECHNICAL DATA
Measuring values temperature, humidity (humidity output configurable)
Output voltage 2x 0..10 V or 0..5 V, min. load 10 kΩ (live-zero configuration via Thermokon USEapp)
Network technology RS485 Modbus, RTU, half-duplex, baud rate 9.600, 19.200, 38.400 or 57600, parity: none (2 stopbits), even
or odd (1 stopbit)
Power supply 15..35 V = or 19..29 V ~ SELV
With alternating voltage, the correct polarity must be ensured
Power consumption max. 0,4 W (24 V =) | 0,8 VA (24 V ~)
Measuring range temp. -20..+80 °C (default setting), optionally configurable via Thermokon USEapp
Measuring range humidity 0..100% rH non-condensing, optionally configurable via Thermokon USEapp (enthalpy, absolute humidity,
dew point)
Accuracy temperature ±0,3 K (typ. at 21 °C)
Accuracy humidity ±2% between 10..90% rH (typ. at 21 °C)
Display (optional) LCD 29x35 mm with RGB backlight
Enclosure enclosure USE-M, PC, pure white,
with removable cable entry
with LCD Display (optional)
cover PC, transparent
Protection enclosure
IP65 according to EN 60529
sensor head
IP30 according to EN 60529
Cable entry M25 for cable max. Ø=7 mm, seal insert for fourfold cable entry
Connection electrical removable plug-in terminal (Mainboard: max. 2,5 mm² / Plug-in card: max 1,5 mm²);
connection wire sensor head to plug RJ12: PVC 0,15 m;
connection wire bush RJ12 to enclosure: PVC 3 m
Sensor head ABS, white, Ø=30 mm
Ambient condition -35..+70 °C, short term condensation
When several BUS devices are supplied by one 24 V AC voltage supply, it is to be ensured that all “positive” operating voltage input terminals (+) of the field devices
are connected and all “negative” operating voltage input terminals (-) (=reference potential) are connected (in-phase connection of field devices).In the case of reversed
polarity at one field device, a supply voltage short-circuit would be caused by that device.
The consequential short-circuit current flowing through this field my cause damage to it. Therefore, pay attention to correct wiring.

Issue date: 12.05.2022 Page 3 / 4
Thermokon Sensortechnik GmbH, Platanenweg 1, 35756 Mittenaar, Germany · tel: [phone] fax: -400 www.thermokon.com· [e-mail]
FT-RDF18+_RS485_Modbus_Datasheet_en.docx © 2022
»CONNECTION PLAN
If the RS485 cable is looped through, connect both cable shields using the enclosed 2-pol. Connect terminal as shown.
FT_RDF18+ RS485 Modbus
Looped through power supply, valid from 08/03/2020 (20216)
UB+
15..35 V = / 19..29 V ~
GND
AOU2
temperature 2*
| 0..10 V
AOU1
humidity
1 | 0..10 V
GND
15..35 V = / 19..29 V ~
UB+
A+
RS485
A+
B
-
B
-
0..5 V
0..10 V
»DIP-SWITCH-SETTINGS
*factory default settings
Termination 120 Ω
Modbus adress
Not active*
active
ON=20(1)*
ON=21(2)
ON=22(4)
ON=23(8)
ON=24(16)
Baud
Sample adress: 26
9600*
19200
Parity
38400
57600
none*
(2-stopbits)
even
(1-stopbit)
odd
(1-stopbit)
none
(1-stopbit)
The modbus address of the device is set in the range of 1 ... 31 (binary encoded) using a 5-pole DIP switch. With address 0 via DIP, an extended
address range (32..247) is available via USEapp.
Address Access Description Resolution / Unit
1
R
relative humidity
0.1
%rF
Register 400 = 1 (Unit SI)
Register 400 = 2 (Unit Imperial)
Address Access Description Resolution / Unit Resolution / Unit
0 R Temperature SI 0.1 °C Imperial 0.1 °F
2
R
Absolute humidity
SI
0.01
g/m³
Imperial
0.01
Gr/ft³
3
R
Enthalpy
SI
0.1
kj/kg
Imperial
0.1
BTU/lb
4
R
Dew point
SI
0.1
°C
Imperial
0.1
°F
Modbus addresses:
USE-RS485 Modbus Interface
A detailed description of the Modbus addresses can be found under the following link: → Download
ON
132 4 5
A+
B-
A+
B-

Page 4 / 4 Issue date: 12.05.2022
Thermokon Sensortechnik GmbH, Platanenweg 1, 35756 Mittenaar, Germany · tel: [phone] fax: -400 www.thermokon.com· [e-mail]
FT-RDF18+_RS485_Modbus_Datasheet_en.docx © 2022
»NOTES ON DISPOSAL
As a component of a large-scale fixed installation, Thermokon products are intended to be used permanently as
part of a building or a structure at a pre-defined and dedicated location, hence the Waste Electrical and Electronic
Act (WEEE) is not applicable. However, most of the products may contain valuable materials that should be recycled
and not disposed of as domestic waste. Please note the relevant regulations for local disposal.
»DIMENSIONS (MM)
»ACCESSORIES (INCLUDED IN DELIVERY)
Mounting base Item No. 631228
Mounting kit universal Item No. 698511
• Cover screw + screw cover• 2 Rawlplugs • 2 Screws (countersunk head) • 2 Screws (rounded head)
»ACCESSORIES (OPTIONAL)
Cable entry M25 USE white, sealing insert 4x Ø=7 mm (4 pcs) Item No. 641364
Filter stainless steel, wire mesh Item No. 231169
M16 Sealing inserts cable entry (packaging unit 10 pcs.)
for wire with Ø
8 mm
Item No
641340