Ascon tecnologic TRH-MINI Installation and operation manual

Ascon Tecnologic - TRH-MINI - ENGINEERING MANUAL - PAG. 1
TRH-MINI
HUMIDITY AND TEMPERATURE
SENSOR
Engineering manual
19/12 - Cod.: ISTR_M_TRH-MINI_E_00_--
ASCON TECNOLOGIC S.r.l.
Viale Indipendenza 56, 27029 - VIGEVANO (PV) ITALY
TEL.: [phone] - FAX: [phone]
http:\\www.ascontecnologic.com
e-mail: [email protected]
FOREWORD
This manual contains the information necessary for the
installation of the product, we therefore recommend that
the utmost attention is paid to the following instructions
and to save it.
This document is exclusive property of Ascon Tecnologic which
forbids any reproduction and disclosure, even in part, of the
document, unless expressly authorized. Ascon Tecnologic
reserves the right to make any formal or functional changes at
any moment and without any notice.
 Ascon Tecnologic and its legal representatives do not as-
sume any responsibility for any damage to people, things or
animals deriving from violation, wrong or improper use or
in any case not in compliance with the instrument features.
Whenever a failure or a malfunction of the device
may cause dangerous situations for persons, thing
or animals, please remember that the plant must be
equipped with additional electromechanical devices
which will guarantee safety.
Disposal
The appliance (or the product) must be
disposed of separately in compliance
with the local standards in force on
waste disposal.
INSTRUMENT DESCRIPTION
General description
The Humidity and Temperature sensor adopt high quality digital
sensors, with reliable performance, high precision, small year
drift, fast response. It is suitable for temperature and humidity
measurement of communication rooms, offices, workshops,
warehouses, hospitals, HVAC, and building automation etc..
The Relative Humidity and the Temperature measurements can be
read through the RS485 Modbus RTU communications port.
The sensor can be mounted horizontally (on the ceiling) or verti-
cally (on the wall) using 2 screws or a DIN rail. The connections
are really easy: only 4 wires to complete the installation.
Instrument description
Power supply: 8... 24 DC
Range: -20... +80°C, 0... 100% RH
TRH-MINI
GND VDC B A
3
2
1
1. +8... 24 VDC Power terminal;
2. GND Power supply ground terminal;
3. A, B RS485 Modbus RTU terminals.
INSTALLATION INFORMATION
Mounting requirements
This instrument is intended for permanent installation, for indoor
use only, in an electrical panel which encloses the rear housing,
exposed terminals and wiring on the back.
Select a mounting location having the following characteristics:
1. It should be easily accessible;
2. There is minimum vibrations and no impact;
3. There are no corrosive gases;
4. There are no water or other fluids (i.e. condensation).
Dimensions
Power supply: 8... 24 DC
Range: -20... +80°C, 0... 100% RH
TRH-MINI
GND VDC B A
45 28
65
35
Ø3.5

Ascon Tecnologic - TRH-MINI - ENGINEERING MANUAL - PAG. 2
Electrical connections
Carry out the electrical wiring by connecting only one wire to each
terminal and according to the following diagrams:
General notes about wiring
1. Do not run input wires together with power cables.
2. When a shielded cable is used, it should be connected at one
point only.
Power supply
Power supply: 8... 24 DC
Range: -20... +80°C, 0... 100% RH
TRH-MINI
GND VDC B A
+−
8... 24 VDC
Serial Interface
Power supply: 8... 24 DC
Range: -20... +80°C, 0... 100% RH
TRH-MINI
GND VDC B A
B
A
RS-485
B
A
Controller
AB AB AB
120Ω
nth
TRH
2nd
TRH
1st
TRH
Notes: 1. RS-485 interface allows to connect up to 30 devices
with one remote master unit.
2. The cable length must not exceed 1.5 km at 9600 baud.
TECHNICAL CHARACTERISTICS
Tecnical specifications
Characteristic Relative Humidity Temperature
Measuring range 0... 100% -20... +80
Resolution 0.1% RH 0.1°C
Accuracy ±3% RH ±0.5°C
Note: When the sensor is external the temperature range is
-40… +120°C
Electrical specifications
Characteristic Value
Supply voltage 8... 24 VDC
Power consumption < 30 mA
General specifications
Characteristic Value
External dimensions 45 x 65 x 28 (L x H x D)
Mounting DIN Rail
2 screws Ø3 mm max.
Weight About 60 g
Work area 10... 20 m2,
with air circulation
Installation position
Horizontal or vertical
Working temperature
-20... 70°C
Ambient humidity
5... 95% (with no condensation)
Case material
PC + ABS
Serial communications
Characteristic Value
Interface type
Isolated RS485
Voltage levels
According to EIA standard
Protocol type
MODBUS RTU
Byte format
8 bit with no parity
Stop bit
1 (one)
Baud rate
Programmable between 1200... 38400 baud
Address
Programmable between 1... 247
HOW TO ORDER
TRH-MINI Relative Humidity and Temperature sensor.
RS485 COMMUNICATIONS
Code system
8 bit binary, hexadecimal 0... F, each word (8 bit) contains 2
hexadecimal characters.
Modbus RTU bits per byte in the protocol
1 Start bit;
8 Data bits (the less important bit must be sent as first);
- No parity;
1 Stop bit.
Error detection domain
CRC-16 (Ciclic Redundacy Check), the lowest is in front, the
highest byte behind.
Communication speed
1200, 2400, 4800, 9600, 19200 baud per second.
The baud rate and the instrument address must be set using the
communications protocol.

Ascon Tecnologic - TRH-MINI - ENGINEERING MANUAL - PAG. 3
Functional domain code in Modbus RTU protocol
Function code Name Description
03
Read holding
register Reads the data measured
06
Preset single
register
Sets the communications
address and the baud rate
Function code 03 - Read holding register
Reads the measured data. Data start address: 0000... 0001.
Data length: 0001... 0002, out of range is invalid; data start ad-
dress + data length is not greather than 2, out of range is invalid.
Note: The date that read is 16 bit data, high byte is in front, low
byte behind.
Data definition: See function code 03H and data comparison table
E.g. 1 Reading the Measured Data
Com-
mand
01 03 00 00 00 02 CRC
ADDR Function Start
address
# of
registers CRC check
Response
01 03 04 00 EA 02 95 CRC 11 bytes
ADDR Function Byte
count
Temp.
(°C)
RH
(%RH) CRC check
Calulation of the measured values: the output value is Data
number divided by 10 defines the Temperature in °C or the the
Relative Humidity in %RH.
In the example:
- The temperature masured value is: 00 EA (Hex.), the actual
value is 0 0EA/10 = 23.4°C. The negative values are repre-
sented by the complement;
- The Relative Humidity measured value is: 02 95 (Hex.) and its
actual value is 02 95/10 = 66.1%RH.
Function code 03H and data comparison table
Address Data content Data description
0000
Temperature Temperature value: 2 bytes
(high byte is in front, low byte is behind)
0001
Humidity Relative Humidity value: 2 bytes
(high byte is in front, low byte is behind)
Function code 06 - Preset single register
Sets the Communications Address and the baud rate.
Data start address: 00 00;
Data Length: 00 01, if not equal to 00 01 the communication
command is invalid.
E.g. 2 Preset the Communication address (changes from 1 to 2)
and the baud rate to 9600 bps).
Com-
mand
01 06 00 00 00 01 02 02 06 CRC
ADDR Function Start
address
# of
registers
Byte
count
Preset
data
CRC
check
Response
01 06 00 00 00 01 CRC
ADDR Function Start
address
# of
registers
CRC
check
Function code 03H and data comparison table
Address Data content Data description
0000
Addr
The higher bits identify the sensor com-
munication Adress, the address range is
01... F7 (Hex.) = 1... 247
bps
The lower 8 bits are the communications
baud rate, the speed range is:
03... 07 (Hex.) = 1200... 19200 bps