DR
R42
M
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1
A
N 0
3
3
6
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9
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OVERVIEW
The DRR42M is a radio receiver which is able to receive
commands from the transceiver antenna Modbus® (DA0421),
featuring two SPDT relay outputs with 6A 230V~ contacts
rating and two LEDs indicating the outputs status and the radio
communication quality. This device is a two channels receiver
designed to switch on loads (more precisely, electro-thermal
valves or circulators) via radio in home or office heating/cooling
systems. It has two channels that have to be associated to
relevant transmitters, wireless thermostat or programmable
thermostat. This system is an optimal solution for buildings in
which wires cannot be laid between thermostats and the
environment to be controlled. Operating on a frequency of
868.150 MHz (LPD) provides the user with all the advantages of
this band, such as the greatest freedom from interference and
greater efficiency in the transmission of the signal.
OPERATION
Each thermostat, programmable thermostat or transceiver
Modbus® antenna sends radio commands to the receiving unit
based on the heating and cooling requirements of the room where
it is located. These radio commands are then received and
decoded by the receiving unit, which is usually installed in the
same room as the boiler or air conditioning equipment. The relay
outputs are turned on or off in the receiving unit depending on the
requirements. These output s can be connected to valves that
control the flow of hot/cold water in the heating/cooling unit
located in the room. While it is operating, the receiver
continuously monitors the status of each channel in order to
detect any transmitter malfunctions.
MECHANICAL DESCRIPTION
LEDs ( and Fig. 1)
On the front panel of the device there are two multicolor LED
which gives information regarding the correct power supply, the
output relays status and the signal strength:
Power supply
When the receiving unit is powered, the LEDs light up and perform
a blinking sequence “green-red-green-red” to indicate the correct
operation of the device. Then the LEDs becomes active depending
on their normal operation and the receiver starts to perform its
normal activity, decoding the signals sent by the transmitters.
Actuator outputs status
During normal operation, each of the LEDs may light up green,
yellow or red. The LED provides several information about the
output and the radio device controlling it.
In general, the following rule should be borne in mind:
- When the LED is lit, regardless of its color, it means that the
corresponding actuator output is ON.
- When the LED is either off or only faintly lit, it means that the
corresponding actuator output is OFF.
- The color of the LED provides information about the quality of
radio communication. See paragraph on
“Checking the signal
strength”
.
- When the LED is continuously blinking it indicates a fault in the
system which requires the user‘s intervention. In this case the
color of the LED has the following meaning:
Green:
Error in the temperature probe of the wireless device.
Yellow:
Wireless device battery low.
Red:
Absence of radio communication.
When the channel is in a fault status and the LED is blinking, it
may blink in two different ways depending on the output relay
status.
C
If the output is inactive the LED will normally remain off but then
emit a short flash, whereas if the output is active, the LED will
normally remain lit and then go off briefly.
SELF-LEARNING BUTTONS ( and Fig. 1)
The device is equipped with two self-learning buttons for setting
up the wireless link between the thermostat (or programmable
thermostat) and the receiver, one button for channel 1 Fig. 1
and one button for channel 2 Fig. 1.
ELECTRICAL CONNECTIONS
The device can be powered at 230V
or 24V . Terminals
L
and
N
supply the receiver at 230V and must be connected to mains
with neutral to terminal
N
. Alternatively connect the power supply
to terminals
a
and
N
to power the device at 24V . Terminals 1, 2
and 3 are the voltage free SPDT relay contacts of the channel 1
output. Terminals 4, 5 and 6 are the voltage free SPDT relay
contacts of the channel 2 output. Figure 7 and 9 shows how to
connect a valve that will be powered when the output is set and
that is when the thermostat calls for heat (heating) using the NO
contact of the relay. Figure 8 and 10 shows how to connect to
the receiver a heat valve and a cold valve when the receiver is set
for regulation with dead band. The outputs, terminals 1 to 6, are
voltage free and insulated with reinforced insulation towards the
other circuits of the receiver. Therefore, the receiver can be
supplied with SELV low voltage (24V ), while controlling a high
voltage load (230V ), as shown in Fig. 9 or 10. In this case 24V
SELV and 230V
cables must be separated complying with current
standards. In particular, it is necessary to secure the two groups of
cables with cable ties separating the SELV wires from the others.
This is required to avoid that the insulation to SELV is reduced in the
event of a wire accidentally disconnects.
CONFIGURING THE SYSTEM
To be able to install several thermostats or transceiver Modbus®
antennae in the same area and to be able to use the multichannel
systems, every thermostat or transceiver Modbus® antennae is
equipped with its own address code. Thermostats or transceiver
Modbus® antennae with different addresses can work at the
same time without interfering each other and therefore controlling
different areas. To memorize the address of the device from which
we want to receive the signals, it is necessary to perform the self-
learning procedure described below. It is possible to repeat several
times the self-learning procedure, the new address will overwrite
the old one stored. It is possible to repeat multiple times the self-
learning procedure, the new address will overwrite the one previously
stored in memory. If it is needed to control both the relay outputs of
the receiver DRR42M with a Modbus® transceiver, perform the self-
learning procedure of only channel 1, because channel 2 will be
automatically managed along with channel 1 by the same Modbus®
register of the transceiver. Anyway, it is possible to manage
separately the two channels by two different channels of the
Modbus® transceiver by performing a self-learning procedure for
each channel. It is also possible to manage one of the channels with
a Modbus® transceiver and the other one by a thermostat or a
programmable thermostat.
Self-learning procedure
- Switch on the receiver: the LEDs blink for a few seconds
during the initialization phase.
- Turn on the thermostat, the programmable thermostat or the
transceiver Modbus® antenna in “test” mode (the activation of
the “test” mode must happen through a specific Modbus®
command coming from a PC or a PLC), then the transmitter
will continuously send an ON command followed by an OFF
command after two seconds. Turn on only one device in the
“test” mode at a time. It is advisable to keep the transmitter in
the same room of the receiver, apart at least one meter each
other.
- Press the self-learning button of the desired channel for a
second Fig.1 for channel 1 and Fig.1 for channel 2. The
self-learning procedure starts: the relevant channel’s LED will
blink quickly yellow.
- As soon as a test command is received, the LED will remain
steadily lit yellow for 7 seconds. During this time the receiver
will continue to receive test commands and memorize only the
signal received with the highest strength. This means that it
will memorize the signal coming from the nearest transmitter
and will thus avoid learning addresses from any transmitters in
test mode which are not meant to be associated to the system.
- After 7 seconds the procedure ends and the LED flashes red-
green-red-green in sequence to indicate that the transmitter
address has been saved.
- The receiver will resume normal operation and the channel
output relay will immediately start to switch ON and OFF every
two seconds following the commands emitted by the
transmitter in “test” mode.
- When using the “test” function it is advisable to check the
strength of the signal received placing the transmitter in the
desired position. To avoid wrong indications due to overlapping
signals, do not test more than one transmitter at a time.
- After verifying that the signal strength is satisfactory, you may
proceed with the final mechanical and electrical installation.
Checking the signal strength
The device constantly indicates the strength of the radio signal
received for each of the two channels. This makes the whole
system simpler to install and regulate; moreover it allows the user
to carry out an instant check on the quality of the radio
communications of each channel.
The signal strength is indicated by each of the two LEDs.
They may light up green, yellow or red according to the quality of
the radio signal received.
Green:
The signal received is good or excellent, radio
communication is reliable.
Yellow:
The signal received is sufficient.
Red:
The signal received is weak, communication is not
reliable.
The status of the output of the actuator that is currently
switched off is signaled with the corresponding LED faintly lit
rather than off, so that the quality of the radio signal can always
be seen.
The receiver indicates two types of signal quality on the LED:
- An immediate analysis of the last command received;
- A long-term analysis of the commands received.
The LED will normally indicate the “long-term” signal quality, based
on the quantity of correct commands received over the previous 90
minutes of operation. In case no command has been received from
the transmitter in the last 90 minutes, the LED will stop showing
the "long-term" analysis and will blink red to show the "absence
of radio communication" fault condition. The signal quality
analysis is non-volatile memorized, so it is possible to evaluate the
channel communication status also after a power cycle. In the
moment a radio command is received, the output LED goes off for
a brief instant and then immediately back on again. For a brief
instant the LED will provide an immediate indication of the last
command received, proportional to the strength of the radio signal
received. If a transmitter is in the “test” mode, the LED on the
receiver will always provide only an “immediate” indication so that
you can instantly assess whether to go ahead with mechanical
installation. If the signal strength is not acceptable try to change
the position of the receiver or transmitter or evaluate the
possibility to install a repeater device (DAPF84) which doubles the
range of the radio commands. Remember that both the transmitter
and receiver must be installed away from metal objects or metal-
reinforced walls that could weaken the radio signals.
NOTE:
The LED may blink to signal a system fault. In this case
the color of the LED has a different meaning, see the paragraph on
“Actuator outputs status”.
DELETION OF A LEARNED ADDRESS
In case you want to delete the address learned on one of the two
channels:
- Press and hold the button of the desired channel
( or Figure 1).
- The relevant LED flashes quickly in yellow and after a few seconds
will flash in a sequence red-green-red-green.
- Release the button, the channel is now inactive. When a channel is
'inactive' on its LED and relay output will remain permanently off.
ASSOCIATION WITH A PROGRAMMABLE
THERMOSTAT
The association of a channel driven by a thermostat to a channel
driven by a programmable thermostat is not possible in this product.
If one of the channels is controlled by a programmable thermostat,
the heating/cooling setting of the programmable thermostat will be
extended to the other channel if it is controlled by thermostat.
OUTPUT REGULATION TYPE
The receiver is factory configured to perform an ON/OFF type
regulation on the output relays with predefined hysteresis. It is
possible to modify the type of regulation choosing a PWM (pulse
width modulation) proportional regulation.
In general you can configure the type of regulation and the
parameters associated with the type of regulation chosen, e.g.
you can change the hysteresis of the ON/OFF regulation or you
can change the proportional band of the PWM regulation.
To configure the type of regulation you need to use a display
thermostat transmitter (i.e. TRD01B, TRD02B, DCW01B) which
D
A
B
A B
A
B
Fig. 1
C
A
B
D
A
B
- ENGLISH -
2 CHANNELS RADIO RECEIVER
FOR HOME AUTOMATION SYSTEMS
