Procon
MelcoRETAIL MINI
FOR INSTALLERS
INSTALLATION MANUAL
Manual version 1.0.6
Firmware version 1.0.3
For safe and correct use, please read this installation manual thoroughly before installing the PROCON
MelcoRETAIL MINI.
Safe
t
Ca
u
Do no
Op
e
The p
r
Shi
e
Use o
reduc
e
ensur
e
CE
This
p
2014/
3
UL 61
Eur
o
Class
produ
c
and r
e
This i
s
interf
e
A
“De
c
been
m
If this
deter
m
interf
e
If nec
e
exper
i
y warnin
g
tion:
t expose to
r
rating Te
m
oduct has
b
lded Signal
nly shielded
the possib
i
s that you
m
Notice:
roduct has
b
5/EU (Low
V
010-1 Elect
pean Union
A products
a
ts may als
o
quire the u
s
a Class A
p
rence in wh
i
laration of
C
ade and is
equipment
d
ined by tur
n
rence by on
Reorient t
h
Relocate
t
Move the
ssary, con
s
enced radio
/
s
ain or moist
perature:
een design
e
Cables:
cables for c
o
lity of interf
e
aintain the
een determ
i
V
oltage Dir
e
rically Safet
y
, Class A:
re intended
be utilized i
er to take a
d
roduct. In a
ch case the
onformity” i
available o
n
oes cause i
n
ing the equ
i
e or more o
f
e receiving
he Procon
M
Procon Mel
c
ult a Procon
television o
r
re.
d to operat
e
nnecting p
e
rence with r
a
appropriate
ned to be in
ctive) and 2
0
Tested.
for use in n
o
n residential
/
equate corr
e
domestic e
n
user may b
e
n accordan
c
request.
terference
w
pment off a
n
the followin
g
antenna.
elcoRETAI
L
oRETAIL M
MelcoRET
A
EMC techn
• i •
Preface
between -2
0
ripherals to
dio commu
EMC classif
i
compliance
11/65/EU (
R
n-residenti
a
/domestic e
n
ctive meas
u
vironment t
h
required to
e with the p
r
ith radio c
o
d on, you a
r
measures:
MINI with
r
INI away fro
m
IL MINI tec
h
ician for ad
d
° C and +6
0
any Procon
nications se
r
cation for th
e
with 2014/3
0
oHS Direc
t
l/non-dome
s
vironments
res.
is product
m
take adequ
a
eceding dir
e
mmunicatio
n
e encourag
e
espect to th
e
the receiv
nical suppo
itional sugg
e
° C
MelcoRETA
vices. Usin
g
intended e
/EU (EMC
D
ive).
tic environ
m
but may ca
u
ay cause r
a
te measure
s
ctives and
s
s services,
w
d to try to c
o
receiver.
r.
t represent
a
stions.
IL MINI devi
shielded c
a
nvironment.
irective),
ents. Class
se interfere
n
dio frequen
c
s.
tandards h
a
w
hich can b
e
orrect the
tive or an
ce to
bles
A
ce
y
s
Disc
l
Wa
r
A
ll pr
o
mater
i
Wa
r
Mitsu
b
We re
by us
use,
n
If the
e
the e
q
aimer
ranty:
ducts manu
f
als for a pe
r
ning:
ishi Electric
serve the ri
g
is believed t
o
or for any in
f
quipment i
s
uipment ma
y
f
actured on
b
iod of three
y
UK assum
e
ht to chang
e
be accura
t
f
ringements
used in a
m
y
be impair
e
ehalf of Mit
s
ears from t
h
s no liability
this manu
a
e and reliab
l
of patents o
r
anor not sp
e
d.
• ii •
subishi Elec
t
e date of d
e
for damage
s
l at any tim
e
e. However
,
r other right
s
cified by th
e
ric UK are
w
livery to th
e
conseque
n
without noti
no respons
of third par
t
manufactu
arranted ag
a
original pur
c
t to the user
ce. The info
r
bility is ass
u
ies resultin
g
er, the prot
e
ainst defecti
haser.
of this prod
u
mation furn
i
med by us
f
from its us
e
ction provid
v
e
ct.
shed
or its
.
ed by
• iii •
Document Amendment Register
Document
Version
Latest
Firmware
Version
Date Author Notes
1.0.0
1.0.0 12/07/17 GD Initial version.
1.0.1 1.0.0 31/07/17 GD
Added information to Connections section regarding connections
to twin/triple/quad and MXZ systems.
Correction made to section 2, the name MAC-399IF replaced
with MAC-333IF.
1.0.2 1.0.1 11/08/17 GD
Voltage/resistance bands changed for setpoint, mode and fan
speed control.
1.0.3 1.0.1 29/09/17 GD Added certification logos
1.0.4 1.0.2 27/11/17 GD
Updates for V1.0.2 firmware.
Sections 7.9, 7.10 and 7.11 updated.
Addition of new Modbus holding registers (see section 12.1).
Firmware revision history table added.
1.0.5 1.0.3 17/01/18 GD
Added section 8. Failsafe AUTO Mode.
Updated sections 7.2 Mode control and 7.3 Fan Speed control.
Firmware revision history table updated.
1.0.6 1.0.3 08/02/18 GD
Corrected text in section 9.Deadband mode to state deadband
mode is enabled by setting DIP switch 2-1 to the ON position.
Any additional notes since printing will be appended to the rear of this document on separate
sheets of paper.
• iv •
Firmware Revision History
Firmware
Version
Date Notes
1.0.0
21/07/17 Release for testing purposes.
1.0.1 25/08/17 Voltage/resistance bands changed for setpoint, mode and fan speed control.
1.0.2 28/11/17
Operation of HEATING relay changed so it only energises when in Heat or Auto mode
when the return air temperature is less than the setpoint.
Operation of COOLING relay changed so it only energises when in Cool or Auto mode
when the return air temperature is greater than the setpoint.
A configurable relay switching delay has been added to prevent rapid switching.
1.0.3 17/01/18 Added Failsafe AUTO mode feature (see section 8. Failsafe AUTO Mode)
1
[
Fig. 1]
A
A CN105/
C
N92 connectiion lead
Page 1
2
[Fig. 2
]
]
Air to air unit
Page 2
Page 3
Contents
Preface ............................................................................................................................................................................. i
Safety warnings ............................................................................................................................................................ i
Disclaimer ..................................................................................................................................................................... ii
Document Amendment Register .................................................................................................................................. iii
Firmware Revision History ........................................................................................................................................... iv
1. Safety precautions ................................................................................................................................................ 5
2. Overview ................................................................................................................................................................ 6
3. Installation ............................................................................................................................................................. 7
3.1. Physical connection ........................................................................................................................................ 7
3.2. Power supply .................................................................................................................................................. 7
3.3. RS-485 connection ......................................................................................................................................... 7
4. DIP switch settings ............................................................................................................................................... 8
4.1. Modbus Slave ID ............................................................................................................................................ 8
4.2. RS-485 communication settings ..................................................................................................................... 9
4.3. Protocol selection ........................................................................................................................................... 9
4.4. Auto Mode / Lock Mode selection .................................................................................................................. 9
4.5. Deadband Mode ............................................................................................................................................. 9
4.6. Setpoint Limiting ........................................................................................................................................... 10
4.7. Timeout ........................................................................................................................................................ 10
4.8. Input type selection ...................................................................................................................................... 10
4.9. Summary ...................................................................................................................................................... 11
5. Connections ........................................................................................................................................................ 12
5.1. Overview ...................................................................................................................................................... 12
5.2. CN92/CN105 ................................................................................................................................................ 12
5.3. RS-485 ......................................................................................................................................................... 12
5.3.1. RS-485 termination resistor ................................................................................................................... 12
5.4. Analogue Inputs ........................................................................................................................................... 13
5.4.1. Input type selection ............................................................................................................................... 13
5.4.2. S.P. ....................................................................................................................................................... 13
5.4.3. MODE ................................................................................................................................................... 13
5.4.4. FAN SPEED .......................................................................................................................................... 13
5.4.5. OCC MODE .......................................................................................................................................... 13
5.5. Digital Inputs................................................................................................................................................. 14
5.5.1. FORCE ON ........................................................................................................................................... 14
5.5.2. FORCE OFF ......................................................................................................................................... 14
5.5.3. AUTO/LOCK MODE .............................................................................................................................. 14
5.5.4. FAULT ................................................................................................................................................... 14
5.6. Relay Outputs ............................................................................................................................................... 15
5.6.1. ON/OFF................................................................................................................................................. 15
5.6.2. HEATING .............................................................................................................................................. 15
5.6.3. COOLING .............................................................................................................................................. 15
5.6.4. FAULT ................................................................................................................................................... 15
5.7. Using Twin / Triple / Quad systems .............................................................................................................. 16
5.7.1. When Fault output is being used ........................................................................................................... 16
5.7.2. When Fault output is not being used ..................................................................................................... 16
5.8. Using single split units in a group ................................................................................................................. 17
5.8.1. When Fault output is being used ........................................................................................................... 17
5.8.2. When Fault output is not being used ..................................................................................................... 17
5.9. Using MXZ split units .................................................................................................................................... 18
6. Status LEDs ........................................................................................................................................................ 19
6.1. Relay Status ................................................................................................................................................. 19
6.2. Communication Status ................................................................................................................................. 19
7. Control for ATA systems ................................................................................................................................... 20
7.1. Setpoint control ............................................................................................................................................ 20
7.2. Mode control................................................................................................................................................. 21
7.3. Fan Speed control ........................................................................................................................................ 22
7.4. Occupancy Mode ......................................................................................................................................... 23
7.5. Force On ...................................................................................................................................................... 24
7.6. Force Off ...................................................................................................................................................... 24
7.7. Auto Mode / Lock Mode ............................................................................................................................... 24
7.7.1. Auto Mode ............................................................................................................................................. 24
7.7.2. Lock Mode ............................................................................................................................................. 24
Page 4
7.8.
External Fault ............................................................................................................................................... 24
7.9. ON/OFF status output .................................................................................................................................. 25
7.10. Heating status output ................................................................................................................................... 25
7.11. Cooling status output .................................................................................................................................... 25
7.12. Fault output .................................................................................................................................................. 26
7.12.1. Using Twin / Triple / Quad systems ....................................................................................................... 26
8. Failsafe AUTO Mode ........................................................................................................................................... 29
8.1. Failsafe trigger thresholds ............................................................................................................................ 29
8.2. Power up ...................................................................................................................................................... 29
8.3. Triggering failsafe AUTO mode .................................................................................................................... 29
9. Deadband mode .................................................................................................................................................. 30
9.1. Settings ........................................................................................................................................................ 30
9.2. Operation ..................................................................................................................................................... 30
9.3. Initialisation .................................................................................................................................................. 31
10. Setpoint Offset .................................................................................................................................................... 32
10.1. Settings ........................................................................................................................................................ 32
10.2. Operation ..................................................................................................................................................... 32
11. Modbus RTU ....................................................................................................................................................... 34
11.1. Modbus background ..................................................................................................................................... 34
11.2. Modbus registers .......................................................................................................................................... 34
11.3. Modbus connections .................................................................................................................................... 34
12. Modbus register tables ...................................................................................................................................... 35
12.1. Holding registers .......................................................................................................................................... 35
12.2. Input registers ............................................................................................................................................... 39
12.3. Discrete Inputs ............................................................................................................................................. 40
12.4. Coils ............................................................................................................................................................. 41
Appendix A – Compatible Air-To-Air units ................................................................................................................. 42
1. Safe
t
Symbols us
e
Warning:
Describes pr
e
Caution:
Describes pr
e
Warning
:
• Ask the d
e
- Imprope
r
• Use the s
p
not appli
e
- Inadequ
a
• Never rep
- If the uni
t
• Have all e
Regulatio
- If the po
w
• Keep the
e
- Contact
m
• To dispo
s
Caution:
• Safely di
s
- Packing
m
- Tear apa
which has
¾ Befor
e
“Safet
y
¾ The “
S
regard
y preca
u
ed in the tex
t
cautions that
cautions that
aler or an au
t
installation by
t
ecified cable
s
d to the termi
n
te connection
a
air the unit. If
t
is repaired im
p
lectric work d
o
ns" and the in
s
er source cap
a
lectric parts
a
ay result in el
e
e of this prod
u
pose of the p
a
aterials, such
rt and throw a
w
not been torn
a
installing the
precautions
”
afety precauti
o
ing safety. Ma
k
tions
should be ob
s
should be ob
s
horised techn
i
he user may r
e
for wiring. M
a
als
nd fastening
m
he controller
m
roperly, electri
c
ne by a licen
s
tructions giv
e
city is inadequ
a
way from any
ctric shock, fir
e
ct, consult y
o
cking materia
l
as nails and ot
h
ay plastic pack
part, they face
unit, make su
r
ns” provide
v
e sure you fo
erved to prev
e
erved to prev
e
cian to install
sult in electric
s
ke the conne
c
ay generate he
ust be repair
e
shock, or fire
m
ed electrician
n in this man
u
te or electric
w
water - washi
n
or smoke
ur dealer
s
er metal or wo
aging bags so
t
the risk of suff
o
e you read all
ery important
low them
nt danger of i
n
nt damage to
the unit
hock, or fire
tions securel
y
at and cause a
ed, consult th
e
ay result
according to
"
al and alway
s
ork is perform
e
g water etc…
oden parts, ma
hat children wil
cation
the
points
jury or death
the unit.
so that any
o
fire
dealer
Electric Facili
t
use a special
d improperly, e
y cause stabs
o
l not play with t
h
to the user.
utside forces
a
y Engineerin
g
circuit
lectric shock a
n
r other injuries
em - If childre
n
cting on the
c
Standard", "I
n
d fire may res
u
play with a pl
a
Page 5
ables are
terior Wire
lt
stic bag
2. Over
v
The Procon
M
S- and P-ser
equipment. I
t
inputs so tha
It also has di
g
The MelcoR
E
the reading i
s
devices thro
u
connection.
P
The MelcoR
E
is needed.
Compatible
A
Caution:
MAC-397IF
a
CN105/CN9
2
Figure 1 sh
o
Figure 2 sh
o
Air units.
iew
elcoRETAIL
ies split air c
o
has digital o
u
t settings suc
h
gital inputs to
TAIL MINI c
o
continuous
t
gh the RS-4
8
lease refer t
o
TAIL MINI is
ir-To-Air mo
d
nd MAC-333
connector is
ws the Melco
ws the CN10
5
MINI Protoc
o
nditioning sy
s
tputs for stat
u
as tempera
t
force certain
ntinuously re
he MelcoRE
T
5 port using
t
the Modbus
powered via
t
el numbers c
IF units cann
o
used.
RETAIL MINI
/CN92 conn
e
l Converter is
tems).It acts
a
s informatio
n
ure set point
c
modes of ope
ds data fro
m
AIL MINI alw
a
he Modbus R
section for fu
r
he CN105/C
N
n be found i
n
t be connect
e
ctor on the i
n
used for rem
s a gateway
such as curr
e
an be set vi
a
ration and fo
r
the system
a
ys stores up
-
TU software
p
ther informati
92 connecto
Appendix A
d when the
M
door unit PC
B
ote monitorin
g
between the
s
nt Heat/Cool
a 0-10V or r
e
indication of
a
nd changes
c
to-date data.
rotocol. Valu
e
on.
on the indo
o
of this docum
elcoRETAIL
that the Mel
c
and control
o
ystem and e
x
mode and F
a
sistive output
3rd party sy
s
onfiguration
w
This data is t
h
s can be rea
d
r unit, hence
n
e
nt.
INI is conn
e
oRETAIL MI
N
f Air-to-Air p
r
ternal third p
a
ult. It has an
a
from a 3rd pa
tem fault.
hen necess
a
en available
t
d
and chang
e
o external p
o
cted, as the
s
I connects t
o
Page 6
oducts (M-,
rty
logue
rty system.
ry. Because
t
o external
d via this
wer supply
ame
on Air-to-
Page 7
3. Installation
3.1. Physical connection
The MelcoRETAIL MINI has a 1 metre flying lead to connect directly into the CN105/CN92 connector on the controller
PCB.
3.2. Power supply
The MelcoRETAIL MINI is powered from the CN105/CN92 air conditioner host connector at 12V DC and therefore
does not require an external power supply.
3.3. RS-485 connection
The MelcoRETAIL MINI has a 3-way screw terminal to provide Modbus RTU communication via RS-485. See chapter
5.3 for more details.
4. DIP
s
The MelcoR
E
There is a b
a
The followin
g
Note: The M
4.1.
M
Any Modbus
binary, wher
e
To get the Sl
1-3 and 1-4
O
When switch
Holding regi
s
Note: Settin
g
Note: Each
M
witch s
e
TAIL MINI h
a
nk of 8 DIP s
w
sections det
a
elcoRETAIL
M
odbus Sl
a
Slave ID in t
h
the switch p
o
ave ID, add t
o
N (1 + 4 + 8
es CONFIG
1
ter (see cha
p
switches C
O
odbus devic
e
ttings
s a total of 1
2
w
itches labell
e
il how the s
w
INI must be
p
ve ID
e range 1 –
3
sitions have
Switch
n
1-
11-21-31-41-5
gether the v
a
= 13).
-1 to 1-5 are
a
ter 12.1 for
m
NFIG 1-1 to
1
connected
o
DIP switche
s
d CONFIG 1
itches are us
e
ower cycled
0 can be cho
s
the following
v
umber
lue for each
s
ll set to the
O
ore details).
-5 all to the
O
n the same
R
s
which are u
s
and a bank
o
d to configu
r
for any chan
g
en using swi
t
v
alues:
A
ddress
v
witch set ON
.
N position th
e
FF position i
s
S-485 netwo
r
ed for config
u
f 4 DIP switc
h
e the MelcoR
E
es to the DIP
ches CONFI
G
alue when
s
set ON
1
2
4
8
16
For example
Slave ID is
s
an invalid c
o
k must have
a
ration of the
es labelled
C
TAIL MINI.
switch chang
1-1 to 1-5.
T
witch is
, to set Slave
et in softwar
e
mbination an
d
unique Slav
e
unit.
ONFIG 2.
es to take eff
e
he address i
s
ID 13 set swi
t
by writing to
d
should not
b
e ID.
Page 8
ct.
set in
ches 1-1,
a Modbus
e used.
Page 9
4.2. RS-485 communication settings
The RS-485 communication settings are set using switch CONFIG 1-6.
When the switch is in the OFF position the Baud Rate and Parity settings are set in software by writing to Modbus
registers (see chapter 12.1).
1-6 RS-485 communication settings
OFF Baud Rate and Parity set in software
ON 9600 baud, no parity
The number of data bits is fixed at 8 and the number of stop bits is fixed at 1.
4.3. Protocol selection
The RS485 protocol is set using DIP switch CONFIG 1-7, currently only Modbus RTU is supported.
When the switch is in the ON position the Modbus RTU protocol is selected.
1-7 Protocol selection
OFF (Reserved for future use)
ON Modbus RTU
4.4. Auto Mode / Lock Mode selection
The function of the LOCK/AUTO MODE digital input is determined by switch CONFIG 1-8.
When the switch is in the OFF position input LOCK/AUTO MODE is used to enable/disable Auto Mode.
When the switch is in the ON position input LOCK/AUTO MODE is used to enable/disable Lock Mode.
1-8 LOCK/AUTO MODE input function
OFF Enable/disable Auto Mode
ON Enable/disable Lock Mode
4.5. Deadband Mode
The Deadband Mode feature can be enabled using switch CONFIG 2-1.
When the switch is in the OFF position Deadband Mode is disabled.
When the switch is in the ON position Deadband Mode is enabled.
2-1 Deadband Mode
OFF Disabled
ON Enabled
Note: Deadband settings can be changed by writing to Modbus registers (see chapter 12.1 for more details).
Page 10
4.6. Setpoint Limiting
The Setpoint Limiting feature can be enabled using switch CONFIG 2-2.
When the switch is in the OFF position Setpoint Limiting is disabled.
When the switch is in the ON position Setpoint Limiting is enabled.
2-2 Setpoint Limiting
OFF Disabled
ON Enabled
Note: Setpoint Limiting settings can be changed by writing to Modbus registers (see chapter 12.1 for more details).
4.7. Timeout
The Timeout feature can be enabled using switch CONFIG 2-3.
When the switch is in the OFF position the Timeout feature is disabled.
When the switch is in the ON position the Timeout feature is enabled.
2-3 Timeout Feature
OFF Disabled
ON Enabled
Note: The timeout value can be changed by writing to a Modbus register (see chapter 12.1 for more details).
4.8. Input type selection
The input type for the four analogue inputs (S.P, MODE, FAN SPEED, OCC MODE) can be configured using switch
CONFIG 2-4.
When the switch is in the OFF position inputs these inputs are set to voltage (0-10VDC) type.
When the switch is in the ON position inputs these inputs are set to resistive () type.
2-4 Analogue input type
OFF Voltage (0-10VDC)
ON Resistive ()
Page 11
4.9. Summary
Switch Description Notes
1-1
Modbus Slave ID
Node ID 1 – 30 (see chapter 4.1).
All OFF = Invalid combination.
All ON = Software selectable Slave ID.
1-2
1-3
1-4
1-5
1-6 Comms Settings
OFF = Baud rate and parity software selectable
ON = 9600 baud, no parity
1-7 Protocol Selection
OFF = (Reserved for future use)
ON = Modbus RTU
1-8 Auto Mode / Lock Mode
OFF = AUTO/LOCK MODE input used to enable Auto Mode
ON = AUTO/LOCK MODE input used to enable Lock Mode
2-1 Deadband Mode
OFF = Deadband Mode disabled
ON = Deadband Mode enabled
2-2 Setpoint Limiting
OFF = Setpoint Limiting disabled
ON = Setpoint Limiting enabled
2-3 Timeout
OFF = Timeout feature disabled
ON = Timeout feature enabled
2-4 Input Type Selection
OFF = Analogue inputs are voltage (0-10VDC) type
ON = Analogue inputs are resistive () type
5. Con
n
5.1. O
v
5.2. C
N
The MelcoR
E
MelcoRETAI
5.3. R
S
The RS-485
To ensur
e
5.3.
On the Melc
o
to this head
e
ections
erview
92/CN10
TAIL MINI fl
y
L MINI does
n
-485
connector ha
s
reliable Mod
b
1. RS-485 te
r
RETAIL MIN
r will enable t
5
ing lead con
n
ot require an
A, B and gr
o
us communi
c
mination re
s
I PCB there’s
he 120 term
ects to either
external pow
e
und (-) conn
e
ations the gr
o
istor
a 2-pin jump
e
ination resist
o
the CN92 or
C
r supply.
ctions.
und must b
e
r header loc
a
r to the RS-4
N105 conn
e
connected t
o
ted next to th
e
8
5 bus.
ctor on the in
d
the Modbus
RS-485 con
oor unit PC
B
Master devic
e
nector. Fittin
g
Page 12
. The
.
a jumper
5.4. A
n
5.4.
DIP switch 2
-
each input in
When set to
t
When set to
t
5.4.
The input la
b
5.4.
The input la
b
5.4.
The input la
b
5.4.
The input la
b
alogue I
n
1. Input type
4 determine
s
dividually; all
t
he voltage r
a
t
he resistanc
e
2. S.P.
elled S.P. ca
n
3. MODE
elled MODE
c
4. FAN SPE
E
elled FAN S
P
5. OCC MOD
elled OCC c
a
puts
selection
the input typ
e
four will be s
e
nge (DIP swi
t
range (DIP
s
be used to
c
an be used t
o
D
EED can be
u
E
n be used to
s
for all four i
n
t to the same
ch 2-4 OFF)
a
witch 2-4 ON
)
ontrol the uni
t
control the
u
sed to contr
o
et the curren
puts, see se
c
type.
voltage bet
w
) any value of
Setpoint, se
e
nit Mode, se
e
l the unit Fan
t occupancy
s
tion 4.8. It is
n
een 0 and 1
0
resistance c
a
chapter 7.1
f
section 7.2 f
o
Speed, see
s
tate, see sec
t
ot possible t
o
VDC can be
a
n be applied
t
or more detai
r more detail
ection 7.3 for
ion 7.4 for m
o
set the inpu
t
pplied to the
t
o the input.
ls.
s.
more details.
re details.
Page 13
type for
input.
5.5. D
i
The four digi
t
of a relay).
5.5.
The input la
b
5.5.
The input la
b
5.5.
The input la
b
switch 1-8.
S
5.5.
The input la
b
details.
gital Inp
u
al inputs are
o
1. FORCE O
N
elled FORC
E
2. FORCE O
F
elled FORC
E
3. AUTO/LO
C
elled AUTO/
L
ee section 7.
7
4. FAULT
elled FAULT
ts
f the volt-fre
e
ON is used t
o
F
OFF is used
K MODE
OCK MODE
i
for more de
t
is used to ind
i
type, so just
force the un
to force the u
n
s used for eit
h
ails.
cate the pres
e
require an o
p
it to switch o
n
nit to switch
o
er the Auto
o
ence of a faul
en or closed
c
, see section
ff, see sectio
n
r Lock functi
o
t with 3rd part
y
ircuit conne
c
7.5 for more
d
7.6 for more
n, depending
equipment,
s
tion (i.e. the
o
etails.
details.
on the state i
ee section 7.
Page 14
utput side
s DIP
8 for more
5.6. R
e
The relay ou
t
5.6.
The ON/OF
F
5.6.
The HEATI
N
temperature
5.6.
The COOLI
N
return air set
5.6.
The FAULT
o
lay Outp
u
puts are use
d
1. ON/OFF
output indic
a
2. HEATING
G output indi
c
setpoint. See
3. COOLING
G output indi
c
point. See se
c
4. FAULT
utput indicat
e
ts
for status in
f
tes whether t
h
ates the unit
section 7.10
f
ates the unit
tion 7.11 for
m
s if there is a
ormation.
e unit is run
n
is in Heat or
A
or more detai
is in Cool or
A
ore details.
fault with the
ing or not, se
uto mode an
d
ls.
uto mode an
unit, see sec
t
e section 7.9
f
the return a
i
d the return a
ion 7.12 for
m
or more deta
i
r temperatur
e
r temperatur
e
ore details.
ils.
is less than t
is greater th
a
Page 15
he
n the
5.7. U
s
It is recomm
e
MelcoRETAI
5.7.
5.7.
ing Twin
nded to use
o
L MINI can b
e
1. When Fau
2. When Fau
/ Triple /
Q
ne MelcoRE
T
used per twi
n
lt output is b
lt output is n
uad sys
t
AIL MINI for
/ triple / qua
e
ing used
ot being use
d
ems
each indoor
u
d system.
nit, however, if the fault outtput is not us
e
Page 16
d then one
5.8. U
s
It is recomm
e
MelcoRETAI
5.8.
5.8.
ing sing
l
nded to use
o
L MINI can b
e
1. When Fau
2. When Fau
e split un
i
ne MelcoRE
T
used per twi
n
lt output is b
lt output is n
ts in a gr
o
AIL MINI for
/ triple / qua
e
ing used
ot being use
d
up
each indoor
u
d system.
nit, however, if the fault outtput is not us
e
Page 17
d then one
5.9. U
s
One MelcoR
E
ing MXZ
TAIL MINI
m
split unit
s
ust be install
e
d for each indoor unit whe
using a MXZ system.
Page 18
6. Stat
u
6.1. R
e
The relay st
a
The LEDs wi
6.2. C
o
When the M
e
The
A
/C AC
K
The RS485
A
s LEDs
lay Stat
u
tus LEDs indi
ll switch ON
w
mmunic
a
lcoRETAIL
M
LED will fla
s
CK LED will
f
s
cate the curr
e
hen the corr
e
tion Stat
u
INI powers u
p
h when there
lash when th
e
nt state of th
e
sponding rel
a
s
both LEDs
w
is valid com
m
re is valid M
o
relay output
s
y energises/
s
ill switch on
t
unication wit
h
dbus RTU c
o
.
witches on.
o indicate it i
s
the indoor u
mmunication
powered.
it.
with a Modbus master dev
i
Page 19
ce.
Page 20
7. Control for ATA systems
When the MelcoRETAIL MINI powers up it automatically starts communicating with the indoor unit.
This chapter describes the control for ATA systems.
7.1. Setpoint control
The analogue input labelled S.P. controls the unit’s Temperature Setpoint.
The DIP switch 2-4 determines whether the input type is voltage (0-10V) or resistance (), see chapter 4.8 for more
details.
S.P.Input
Temperature
Setpoint(°C)
Voltage(V)
Resistance(KΩ)
Below0.75 Below0.75 Uncontrolled
0.75–1.25 0.75–1.25 17
1.25–1.75 1.25–1.75 18
1.75–2.50 1.75–2.50 19
2.50–3.25 2.50–3.25 20
3.25–3.75 3.25–3.75 21
3.75–4.25 3.75–4.25 22
4.25–5.00 4.25–5.00 23
5.00–5.75 5.00–5.75 24
5.75–6.25 5.75–6.25 25
6.25–6.75 6.25–6.75 26
6.75–7.50 6.75–7.50 27
7.50–8.25 7.50–8.25 28
8.25–8.75 8.25–8.75 29
8.75–10.0 8.75–10.0 30
Above10 Above10 Uncontrolled
When the MelcoRETAIL MINI powers up it will read the S.P. input and the temperature setpoint will be determined
based on data in the table above. A command will then be sent to the indoor unit to set this setpoint value.
If the S.P. input changes such that a new temperature setpoint band is entered, a command will be sent to the indoor
unit to change the setpoint accordingly. There is 0.1V / 0.1k hysteresis applied to each band change to prevent rapid
changes to the setpoint.
When LOCK mode is enabled (see chapter 4.4) the command to set the temperature setpoint will be sent every 5
seconds. This will effectively revert any changes made via a local wall controller.
Page 21
7.2. Mode control
The input labelled MODE controls the unit’s Operating Mode.
The DIP switch 2-4 determines whether the input type is voltage (0-10V) or resistance (), see chapter 4.8 for more
details.
MODEInput
OperatingMode
Voltage
(V)
Resistance
(kΩ)
0.1–2.0 0.0–2.0 Fan
2.0–3.0 2.0–3.0 Uncontrolled
3.0–4.5 3.0–4.5 Heat
4.5–5.5 4.5–5.5 Uncontrolled
5.5–7.0 5.5–7.0 Cool
7.0–8.0 7.0–8.0 Uncontrolled
8.0–10 8.0–10 Auto
Above10 Above10.0 Uncontrolled
When the MelcoRETAIL MINI powers up it will read the MODE input and the operating mode will be determined based
on data in the table above. A command will then be sent to the indoor unit to set the mode accordingly.
If the MODE input changes such that a mode band is entered, a command will be sent to the indoor unit to change the
mode accordingly. There is 0.1V / 0.1k hysteresis applied to each band change to prevent rapid changes to the
mode.
When LOCK mode is enabled (see chapter 4.4) the command to set the mode will be sent every 5 seconds. This will
effectively revert any changes made via a local wall controller.
Note: When the voltage on all four analogue inputs decrease below 0.1V (or if the resistance increases above
100kΩ (i.e. open circuit)) the unit will enter a failsafe state and the Mode will be set to AUTO. See section 8.
Failsafe AUTO Mode for more details).
Page 22
7.3. Fan Speed control
The input labelled FAN SPEED controls the unit’s Fan Speed.
The DIP switch 2-4 determines whether the input type is voltage (0-10V) or resistance (), see chapter 4.8 for more
details.
FANSPEEDInput
FanSpeed
Voltage
(V)
Resistance
(kΩ)
0.1–2.0 0.0–2.0 Low
2.0–3.0 2.0–3.0 Uncontrolled
3.0–4.5 3.0–4.5 Mid1
4.5–5.5 4.5–5.5 Uncontrolled
5.5–7.0 5.5–7.0 Mid2
7.0–8.0 7.0–8.0 Uncontrolled
8.0–10 8.0–10 High
Above10 Above10.0 Uncontrolled
When the MelcoRETAIL MINI powers up it will read the FAN SPEED input and the fan speed will be determined based
on data in the table above. A command will then be sent to the indoor unit to set the fan speed accordingly.
If the FAN SPEED input changes such that a new fan speed band is entered, a command will be sent to the indoor unit
to change the fan speed accordingly. There is 0.1V / 0.1k hysteresis applied to each band change to prevent rapid
changes to the fan speed.
When LOCK mode is enabled (see chapter 4.4) the command to set the fan speed will be sent every 5 seconds. This
will effectively revert any changes made via a local wall controller.
Page 23
7.4. Occupancy Mode
The input labelled OCC MODE determines the temperature deadband settings for the indoor unit.
The DIP switch 2-4 determines whether the input type is voltage (0-10V) or resistance (), see chapter 4.8 for more
details.
OCCInput
DeadbandSettings
Voltage
(V)
Resistance
(kΩ)
Below1.5 Below2.5 Uncontrolled
1.5–2.5 2.5–4.0
Unoccupied
Heatto16ºC,Coolto26ºC
2.5–4.5 4.0–5.5 Uncontrolled
4.5–5.5 5.5–7.0
StaffIn
Heatto18ºC,Coolto24ºC
5.5–6.5 7.0–8.5 Uncontrolled
6.5–7.5 8.5–10.0
Occupied
Heatto21ºC,Coolto23ºC
Above7.5
Above10.0 Uncontrolled
When the MelcoRETAIL MINI powers up it will read the OCC MODE input and the deadband settings will be updated
accordingly based on the data in the table above. Deadband mode will be enabled even if it’s not enabled using DIP
switch 2-1 (see chapter 4.5). Additionally, deadband control using the OCC MODE input will take precedence over the
deadband control activated by DIP switch 2-1.
If the OCC MODE input changes such that a new deadband settings band is entered, the deadband settings will be
updated accordingly. There is 0.1V / 0.1k hysteresis applied to each band change to prevent rapid changing of
Deadband settings.
Note: These Deadband settings can be changed by writing to Modbus registers (see chapter 12.1 for more details).
Note: The 4 degree offset AND dual setpoint features must be disabled on the indoor unit for the Occupancy
Mode feature to operate correctly.
Page 24
7.5. Force On
When the FORCE ON volt free input is closed a command will be sent to the indoor unit at least once every 10
seconds to switch the drive ON. This will effectively revert any changes made via a local wall controller within 10
seconds.
Attempts to switch the drive OFF using Modbus will be ignored.
The FORCE ON input has a higher priority than the FORCE OFF input, so if both inputs are in the closed state the
indoor unit drive will be forced ON every 10 seconds.
7.6. Force Off
When the FORCE OFF volt free input is closed a command will be sent to the indoor unit at least once every 10
seconds to switch the drive OFF. This will effectively revert any changes made via a local wall controller within 10
seconds.
Attempts to switch the drive ON using Modbus will be ignored.
The FORCE ON input has a higher priority than the FORCE OFF input, so if both inputs are in the closed state the
indoor unit drive will be forced ON every 10 seconds.
7.7. Auto Mode / Lock Mode
The operation of the AUTO/LOCK MODE input is determined by the state of DIP switch 1-8 (see chapter 4.4 for
details). When this DIP switch is OFF the input is used to enable Auto Mode. When the DIP switch is ON the input is
used to enable Lock mode.
7.7.1. Auto Mode
When Auto Mode is enabled, when the AUTO/LOCK MODE input is momentarily closed a command is sent to the
indoor unit to set the operating mode to AUTO.
If the timeout feature is enabled (see chapter 4.7 for details) then a command to set the unit to operate in FAN mode
will be sent after a configurable length of time.
7.7.2. Lock Mode
When Lock Mode is enabled commands to set the following settings will be sent every 5 seconds:
- Operating Mode (command only sent if the MODE input is controlling the Mode)
- Temperature Setpoint (command only sent if the S.P. input is controlling the Setpoint)
- Fan Speed (command only sent if the FAN SPEED input is controlling the Fan Speed)
7.8. External Fault
When the FAULT input is closed it is assumed a fault is present with external equipment. Whilst the FAULT input is
closed the FAULT relay output will be energised.
Page 25
7.9. ON/OFF status output
The ON/OFF relay output will be energised if the indoor unit drive is currently set to ON, otherwise the output will be
de-energised.
Upon a change to the ON/OFF state there is a delay before the relay changes state. The default delay is 30 seconds
but this is configurable via a Modbus register (see Modbus section 12.1 - Holding registers).
7.10. Heating status output
The HEATING relay output will de-energise when the unit drive is OFF or when the operating mode is not Heat or Auto.
When in Heat or Auto mode the relay will energise when the return air temperature is less than or equal to the
temperature setpoint minus 1ºC for a period of at least 30 seconds. It will de-energise if the return air temperature
increases so it’s greater than or equal to the temperature setpoint.
The 1ºC offset is a configurable value which can be changed via Modbus (see Modbus section 12.1 - Holding
registers). The default value is 1ºC.
The 30 second delay is a configurable value which can be changed via Modbus (see Modbus section 12.1 - Holding
registers). The default value is 30 seconds.
The following sequence of events show how the HEATING relay will operate (with 1ºC offset and 30 second delay):
Setpoint 21, Inlet Temp 23 – Relay = OFF
Setpoint 21, Inlet Temp 22 – Relay = OFF
Setpoint 21, Inlet Temp 21 – Relay = OFF
Setpoint 21, Inlet Temp 20 – Relay = ON*
Setpoint 21, Inlet Temp 19 – Relay = ON
Setpoint 21, Inlet Temp 20 – Relay = ON
Setpoint 21, Inlet Temp 21 – Relay = OFF*
*after a 30 second delay
7.11. Cooling status output
The COOLING relay output will de-energise when the unit drive is OFF or when the operating mode is not Cool or
Auto.
When in Cool or Auto mode the relay will energise when the return air temperature is greater than or equal to the
temperature setpoint plus 1ºC for a period of at least 30 seconds. It will de-energise if the return air temperature
decreases so it is less than or equal to the temperature setpoint.
The 1ºC offset is a configurable value which can be changed via Modbus (see Modbus section 12.1 - Holding
registers). The default value is 1ºC.
The 30 second delay is a configurable value which can be changed via Modbus (see Modbus section 12.1 - Holding
registers). The default value is 30 seconds.
The following sequence of events show how the COOLING relay will operate (with 1ºC offset and 30 second delay):
Setpoint 21, Inlet Temp 19 – Relay = OFF
Setpoint 21, Inlet Temp 20 – Relay = OFF
Setpoint 21, Inlet Temp 21 – Relay = OFF
Setpoint 21, Inlet Temp 22 – Relay = ON*
Setpoint 21, Inlet Temp 23 – Relay = ON
Setpoint 21, Inlet Temp 22 – Relay = ON
Setpoint 21, Inlet Temp 21 – Relay = OFF*
Setpoint 21, Inlet Temp 20 – Relay = OFF
*after a 30 second delay
7.12.
The FAULT
r
- Th
e
- Th
e
- Th
e
7.1
2
It is recomm
e
MelcoRETAI
When Fault
Fault
elay will be e
n
4-digit fault
c
re is a comm
u
FAULT digit
a
.1. Using
T
nded to use
o
L MINI can b
e
output is bei
output
ergised whe
n
ode read fro
m
nication faul
t
l input is in t
h
win / Triple /
ne MelcoRE
T
used per twi
n
ng used
ever any of t
h
the indoor u
n
between the
e closed posi
t
Quad syste
m
AIL MINI for
/ triple / qua
he following
a
it is a value
o
MelcoRETAI
L
t
ion.
s
each indoor
u
d system.
re true:
ther than 80
0
MINI and in
d
nit, however,
0.
oor unit.
if the fault outtput is not us
e
Page 26
d then one
When Fault
Using sin
g
It is recomm
e
MelcoRETAI
When Fault
output is no
t
le split u
n
nded to use
o
L MINI can b
e
output is bei
being used
its in a gr
o
ne MelcoRE
T
used per twi
n
ng used
up
AIL MINI for
/ triple / qua
each indoor
u
d system.
nit, however, if the fault outtput is not us
e
Page 27
d then one
When Fault
Using M
XZ
One MelcoR
E
output is no
t
split uni
t
TAIL MINI
m
being used
s
ust be installed for each indoor unit whe
using a MXZ system.
Page 28
Page 29
8. Failsafe AUTO Mode
The four analogue inputs for control of Setpoint, Mode, Fan Speed and Occupancy would typically be connected to a
third party BMS. In the event of the BMS being switched off or becoming disconnected the MelcoRETAIL MINI will set
the Mode to AUTO.
8.1. Failsafe trigger thresholds
When configured to use 0-10V inputs, failsafe mode will be triggered when the voltage on each of the inputs decreased
below 0.1V.
When configured to use resistance inputs, failsafe mode will be triggered when the resistance on each of the inputs
increases above 100k (i.e. open circuit).
8.2. Power up
It is possible to use the MelcoRETAIL MINI without a connection to a BMS hence without using the four analogue
inputs. On power up the inputs will be checked to see if they are all below the trigger threshold (or open circuit). If they
are the failsafe mode will not be triggered and the MelcoRETAIL MINI will start normal operation.
8.3. Triggering failsafe AUTO mode
If at any time since power up any of the four inputs are below the trigger threshold (or open circuit) the failsafe mode
becomes ‘armed’. Then if all four inputs are below the trigger threshold (or open circuit) the failsafe mode will activate.
When failsafe mode activates the Mode will be set to AUTO once. It will not continuously set AUTO mode so can be
overridden by a wall controller or through a Modbus command.
9. Dea
d
The deadba
n
Note: The 4
Mode featu
r
9.1. S
e
There are tw
o
changed via
The Cooling
will be assu
m
9.2. O
p
When enabl
e
Temperatur
e
While the ro
o
Whilst in HE
A
Whilst in FA
N
setpoint of 1
9
Whilst in CO
O
Whilst in FA
N
setpoint of 2
8
The followin
g
band m
o
d mode is en
degree offs
e
e to operate
ttings
o
settings, th
e
Modbus, refe
r
Setpoint mus
t
ed.
eration
d, the Melco
R
.
m temperatu
r
T mode, if th
mode, if the
ºC.
L mode, if t
h
mode, if the
ºC.
image show
s
de
abled by setti
n
t AND dual s
correctly.
Heating Set
p
to the Modb
u
be at least 2
º
ETAIL MINI
c
e is less tha
n
e room temp
e
temperature
r
e room temp
e
room temper
a
this graphic
a
g DIP switch
etpoint featu
oint (default
1
s register ta
b
C greater th
a
ontrols the
M
the Heating
S
rature rises
a
ises above t
h
rature falls b
e
ture falls bel
o
lly (assumin
g
2-1 ON.
res must be
9º) and Cool
les for more i
n the Heatin
g
ode and Te
m
etpoint the u
bove the He
a
e Cooling Se
t
e
low the Coo
l
w the Heati
n
a Heating S
e
disabled on
t
ing Setpoint (
d
nformation.
Setpoint, oth
perature Set
p
nit will be set
ting Setpoint
point the unit
ing Setpoint
–
g Setpoint th
e
tpoint of 19º
C
he indoor u
n
efault 23ºC).
erwise the de
f
oint based o
n
t
o HEAT mod
1ºC the unit
will be set to
1ºC the unit
w
unit will be s
e
and a Cooli
n
it for the De
a
These value
s
fault values g
the Room (r
e
e with a setp
o
will be set to
COOL mode
w
will be set to
F
et to HEAT m
g Setpoint of
Page 30
dband
can be
iven above
turn air)
int of 28ºC.
FAN mode.
w
ith a
AN mode.
ode with a
23ºC):
Page 31
9.3. Initialisation
When the MelcoRETAIL MINI powers up it will set the mode, which will be determined by the room temperature.
If less than the Heating Setpoint the unit will be set to HEAT mode with a setpoint of 28ºC.
If greater than or equal to the Cooling Setpoint the unit will be set to COOL mode with a setpoint of 19ºC.
If between the Heating and Cooling Setpoints the unit will be set to FAN mode.
10. S
e
Note: The 4
Offset featu
r
10.1.
There are tw
o
Setpoint.
The BMS Vi
r
if the Melco
R
The BMS R
o
lost and res
e
10.2.
In some situ
a
accurate te
m
the differenc
e
setpoint.
The new te
m
Temperatur
e
As a hypoth
e
temperature
the indoor u
n
When the B
M
tpoint
O
degree offs
e
e to operate
Setti
n
o
settings whi
tual Setpoint
c
ETAIL MINI l
o
om Tempera
t
t to zero upo
n
Oper
a
tions a 3rd p
a
perature rea
d
between th
e
perature set
p
Setpoint =
R
tical exampl
e
remaining co
n
it’s temperat
u
S Room Te
m
ffset
t AND dual s
correctly.
gs
ch are applic
a
an be chang
e
ses power.
ure can be c
h
the MelcoR
E
tion
rty room tem
p
ing than the
r
se two temp
e
oint is calcul
a
eturn Air T
e
, consider th
e
stant at 22º
C
re setpoint.
perature rea
c
etpoint featu
ble to the Se
t
d using Mod
b
anged using
M
TAIL MINI lo
s
erature sens
o
eturn air tem
p
rature readin
g
ted using the
mperature –
BMS Virtual
S
. As the BMS
hes 18ºC th
e
res must be
t
point Offset f
e
bus and is st
o
odbus but i
s
ing power.
r connected
t
erature of th
e
s and comp
e
following equ
(BMS Room
Setpoint bein
g
Room Temp
e
Temperatur
e
disabled on
t
ature, BMS
R
red in non-vo
not stored in
t
o a BMS or
o
indoor unit.
T
nsate by adj
u
ation:
Temperatur
e
set to 21ºC
a
rature decre
a
Setpoint = 2
2
he indoor u
n
oom Tempe
r
latile memory
non-volatile
m
ther controlle
r
he MelcoRE
T
sting the ind
o
– BMS Virt
u
nd the indoo
r
ses the Melc
o
– (18 – 21)
=
it for the Se
t
ature and B
M
so the value
emory, so th
may provide
AIL MINI ca
n
or unit’s tem
p
al Setpoint)
r unit return a
oRETAIL MI
N
25ºC.
Page 32
point
S Virtual
is retained
e value is
a more
calculate
erature
ir
I increases
Page 33
Hysteresis has been built in to prevent the temperature setpoint from rapidly changing.
The setpoint offset will only operate correctly if the BMS Room Temperature is periodically updated via Modbus, to
ensure the MelcoRETAIL MINI always has an up to date reading.
If the BMS Room Temperature is set to 0ºC (which it will be on power up) the setpoint offset feature will be disabled. It
will only activate when the BMS Room Temperature is greater than 0ºC.
Note: To disable the feature without removing the MelcoRETAIL MINI power, simply set the BMS Room
Temperature to 0ºC via Modbus.
11. M
o
11.1.
Modbus is a
Slaves.
Slave device
Master. Slav
e
for sending
c
bus at any o
n
Modbus is m
on the same
Each Slave
d
Master send
s
11.2.
Modbus Sla
v
The register
t
Register
N
Discrete I
n
Coil
Input Reg
Holding Re
11.3.
For commun
connection d
Caution:
The RS-485
shield shoul
d
Caution:
RS-485 has
p
and all ‘GND
Caution:
The RS-485
dbus R
T
Modb
master-slave
s simply wait
s do not hav
e
ommands to
s
e time, but u
p
ost commonl
y
bus.
evice must h
a
will contain
t
Modb
e devices sto
t
ypes are su
m
ame
R
put
D
ister
A
gister A
n
Modb
ication over
R
iagrams belo
w
cable must b
e
be connecte
d
olarised dat
a
’s are connec
cable must b
e
U
us backg
r
protocol, whi
c
until they rec
e
the ability t
o
lave devices
to 247 slav
e
used over R
S
ve a unique
his Slave ID
a
us regist
e
re data in reg
i
marised belo
egister Typ
e
Digital Input
igital Output
nalogue Inpu
alogue Outp
u
us conne
c
S-485 all 3 c
o
.
a shielded d
to GND at
o
connections
.
ted together.
daisy-chain
e
ound
h means the
r
ive a comma
n
send comm
a
and receivin
g
s can be con
n
-485, which
D on the bus
,
nd only the
S
rs
sters. There
a
w:
Read o
n
a value
Read a
n
t
Read o
n
value (
0
t
Read a
n
which
h
tions
nnections ar
e
ta cable. Ma
ne end only.
It is crucial t
h
d in a bus ne
t
e are two typ
e
nd from a Ma
s
nds to other
d
data. Modbu
ected at a ti
m
is a hardwar
e
which is ref
e
lave with tha
t
re four regist
nly register u
s
of 0 or 1.
nd write acce
s
nly register u
s
-65535)
nd write acce
s
olds a 16-bit
v
needed. Th
e
ins flex or oth
at all ‘A’s ar
e
t
work. T-junct
s of Modbus
ter, act upon
evices on th
e
s only permit
s
e.
standard all
o
rred to as a
S
Slave ID will
er types and
e
Descri
p
ed for holdin
g
sible registe
r
ed for status
sible registe
r
alue (0-6553
se are label
e
er unshielded
connected t
o
ions (e.g. sta
r
device, Modb
that comman
bus. Master
there to be
o
wing multiple
lave ID. Each
reply.
ach type has
tion
status infor
m
which holds
a
information w
h
used for stat
u
5
)
d A, B and G
cable should
gether, all ‘B’
s
network wiri
n
us Masters a
n
d and send a
devices are r
e
ne Master d
e
devices to b
e
Modbus co
m
its own regis
t
ation which
h
value of 0 o
r
hich holds a
1
s informatio
n
ND. Please r
not be used.
are connect
e
g) are not pe
r
Page 34
d Modbus
reply to the
sponsible
vice on the
connected
mand the
er bank.
olds
1.
6-bit
e
fer to the
The cable
d together
mitted.
Page 35
12. Modbus register tables
Some BMS controllers can only read Modbus Holding Registers, so the MelcoRETAIL MINI also exposes all Discrete,
Coil and Input Registers as Holding Registers. The Discrete Input registers and Input registers are not writable so their
equivalent Holding Register is read only and marked [READ ONLY].
Some BMS controllers may not be able to read signed register values (i.e. values which can be negative in value), so
the MelcoRETAIL MINI also exposes an unsigned version of those registers (these registers will not return a negative
value).
12.1. Holding registers
Holding Registers are read using function code 03 and written to using either function code 06 or 16. Function code 06
is used when writing to a single holding register, function code 16 is used for writing to multiple holding registers in the
same command.
Holding Registers (Analogue Outputs)
Register Name Address
Modicon
Address
Details
Drive Mode 0 40001
1 = Heating
2 = Humidity reduction
3 = Cooling
7 = Ventilation, clean air operation
8 = Auto Operation
9 = i-see heating operation
*
10 = i-see humidity reduction*
11 = i-see cooling *
* indicates a read only value, writing this value will
have no effect
Temperature Setpoint 1 40002
Temperature value in °C multiplied by 10.
e.g. value 200 = 20°C
Fan Speed 2 40003
0 = Auto
2 = Quiet
3 = Weak
5 = Strong
6 = Very strong (SH i)
Air Direction 3 40004
0 = Auto
1 = Position 1
2 = Position 2
3 = Position 3
4 = Position 4
5 = Position 5
7 = Swing
Modbus Slave ID 4 40005 Values 1 – 247 valid
Page 36
Holding Registers (Analogue Outputs)
Register Name Address
Modicon
Address
Details
Modbus RS-485 Baud Rate 5 40006
0 = 9600
1 = 1200
2 = 2400
3 = 4800
4 = 9600
5 = 14400
6 = 19200
7 = 28800
8 = 38400
9 = 56000
10 = 57600
11 = 115200
RS-485 Parity Type 6 40007
0 = None
1 = Even
2 = Odd
Drive On/Off 7 40008
0 = Drive OFF
1 = Drive ON
Room Temperature
[READ ONLY]
8 40009
Temperature value in °C multiplied by 10.
e.g. value 200 = 20°C
Fault Code (hex)
[READ ONLY]
9 40010
0x8000 = No error
0x6999 = Bad communication with indoor unit
(Refer to indoor unit documentation for description of
other fault code values)
Firmware Version
[READ ONLY]
10 40011 MelcoRETAIL MINI firmware version
Modbus Comms Counter
[READ ONLY]
11 40012
Value of a counter which increments upon every valid
Modbus command received. Value is automatically
reset to zero when value exceeds 65535.
Fault Code (decimal)
[READ ONLY]
12 40013
8000 = No error
6999 = Bad communication with indoor unit
(Refer to indoor unit documentation for description of
other fault code values)
System Type Detected
[READ ONLY]
13 40014
0 = ATA
1 = ATW
Deadband Enabled State
[READ ONLY]
14 40015
0 = Deadband disabled (DIP switch 8 OFF)
1 = Deadband enabled (DIP switch 8 ON)
BMS Room Temperature (signed) 15 40016
Signed temperature value in ºC multiplied by 10.
0xFF9C = -10ºC … 0x01F4 = 50ºC
BMS Room Temperature 16 40017
Temperature value in ºC multiplied by 10.
0 = 0ºC … 500 = 50ºC
BMS Virtual Setpoint 17 40018 Temperature value in ºC
Deadband Heating Setpoint 18 40019
Temperature in ºC (default 19ºC).
Value must be at least 2ºC lower than the Deadband
Cooling Setpoint.
Deadband Cooling Setpoint 19 40020
Temperature in ºC (default 23ºC).
Value must be at least 2ºC higher than the Deadband
Heating Setpoint.
Auto Mode Setpoint High Limit 32 40033 Temperature in ºC (default 30ºC).
Auto Mode Setpoint Low Limit 33 40034 Temperature in ºC (default 16ºC).
Page 37
Holding Registers (Analogue Outputs)
Register Name Address
Modicon
Address
Details
Cooling Mode Setpoint High Limit 34 40035 Temperature in ºC (default 30ºC).
Cooling Mode Setpoint Low Limit 35 40036 Temperature in ºC (default 16ºC).
Heating Mode Setpoint High Limit 36 40037 Temperature in ºC (default 30ºC).
Heating Mode Setpoint Low Limit 37 40038 Temperature in ºC (default 16ºC).
--- Occupancy Mode --In Occupancy Cooling Setpoint
38 40039
Temperature in ºC (default 23ºC).
Value must be at least 2ºC higher than the In
Occupancy Heating Setpoint.
--- Occupancy Mode --In Occupancy Heating Setpoint
39 40040
Temperature in ºC (default 21ºC).
Value must be at least 2ºC lower than the In
Occupancy Heating Setpoint.
--- Occupancy Mode --Staff In Cooling Setpoint
40 40041
Temperature in ºC (default 24ºC).
Value must be at least 2ºC higher than the Staff In
Heating Setpoint.
--- Occupancy Mode --Staff In Heating Setpoint
41 40042
Temperature in ºC (default 18ºC).
Value must be at least 2ºC lower than the Staff In
Heating Setpoint.
--- Occupancy Mode --Unoccupied Cooling Setpoint
42 40043
Temperature in ºC (default 26ºC).
Value must be at least 2ºC higher than the
Unoccupied Heating Setpoint.
--- Occupancy Mode --Unoccupied Heating Setpoint
43 40044
Temperature in ºC (default 16ºC).
Value must be at least 2ºC lower than the
Unoccupied Heating Setpoint.
Deadband Cooling Setpoint 44 40045 Temperature in ºC (default 23ºC)
Deadband Heating Setpoint 45 40046 Temperature in ºC (default 19ºC)
Auto Mode Timeout 46 40047
Value in seconds (default 300 seconds).
The length of time before Auto Mode ends and the
unit switches to FAN mode.
Relay Manual Override Start/Stop 51 40052
Write value 1 to allow relay outputs to be overridden
using Modbus registers 52 – 55.
Write value 0 to end the manual override and return
relays to their normal operating state.
Note the manual override will timeout after 20
minutes and the relays will return to their normal
operating state.
Relay 1 Override State
(ON/OFF)
52 40053
If the relay manual override has been enabled using
Modbus register 51 then writing a value 0 to this
register will de-energise the relay.
Writing value 1 will energise the relay.
Relay 2 Override State
(HEATING)
53 40054
If the relay manual override has been enabled using
Modbus register 51 then writing a value 0 to this
register will de-energise the relay.
Writing value 1 will energise the relay.
Relay 3 Override State
(COOLING)
54 40055
If the relay manual override has been enabled using
Modbus register 51 then writing a value 0 to this
register will de-energise the relay.
Writing value 1 will energise the relay.
Page 38
Holding Registers (Analogue Outputs)
Register Name Address
Modicon
Address
Details
Relay 4 Override State
(FAULT)
55 40056
If the relay manual override has been enabled using
Modbus register 51 then writing a value 0 to this
register will de-energise the relay.
Writing value 1 will energise the relay.
Auto Mode Timeout Override 56 40057
If the Auto Mode input has been triggered the unit will
run in Auto mode for a configurable length of time.
This register can be used to temporarily override this
timeout value.
e.g. Trigger Auto Mode and wait for the unit to switch
to Auto mode. Now write value 60 to this Modbus
register. Now after 60 seconds the unit will leave
Auto Mode and run in Fan mode.
Heating Relay Temperature Offset 57 40058
When in Heat or Auto mode this value determines
how far the return air temperature must decrease
below the temperature setpoint for the HEATING
relay to energise.
The value is in ºC.
Cooling Relay Temperature Offset 58 40059
When in Cool or Auto mode this value determines
how far the return air temperature must increase
above the temperature setpoint for the COOLING
relay to energise.
The value is in ºC.
Relay Switching Delay 59 40060
This value determines how long the delay will be
before the ON/OFF, HEATING and COOLING relays
change state.
The value is in Seconds.
Page 39
12.2. Input registers
Input Registers are read using function code 04.
Note the values of all Input registers have corresponding Holding registers which can be used instead.
Input Registers (Analogue Inputs)
Register Name Address
Modicon
Address
Details
Room Temperature 0 30001
Temperature value in °C multiplied by 10.
e.g. value 200 = 20°C
Fault Code (hex) 1 30002
0x8000 = No error
0x6999 = Bad communication with indoor unit
(Refer to indoor unit documentation for description of
other fault code values)
Firmware Version 3 30004 MelcoRETAIL MINI firmware version
Modbus Comms Counter 5 30006
Value of a counter which increments upon every valid
Modbus command received. Counter is reset to zero
when value exceeds 65535.
Fault Code (decimal) 8 30009
8000 = No error
6999 = Bad communication with indoor unit
(Refer to indoor unit documentation for description of
other fault code values)
Unused 9 30010
Current DIP Switch Values 10 30011
Occupancy Mode Input Value
(Least significant register)
11 30012
Value in mV if inputs are set to Voltage type.
Value in if inputs are set to Resistance type.
Occupancy Mode Input Value
(Most significant register)
12 30013
Fan Speed Input Value
(Least significant register)
13 30014
Value in mV if inputs are set to Voltage type.
Value in if inputs are set to Resistance type.
Fan Speed Input Value
(Most significant register)
14 30015
Mode Input Value
(Least significant register)
15 30016
Value in mV if inputs are set to Voltage type.
Value in if inputs are set to Resistance type.
Mode Input Value
(Most significant register)
16 30017
Setpoint Input Value
(Least significant register)
17 30018
Value in mV if inputs are set to Voltage type.
Value in if inputs are set to Resistance type.
Setpoint Input Value
(Most significant register)
18 30019
Page 40
12.3. Discrete Inputs
Discrete Input Registers are read using function code 02.
Discrete Inputs (Digital Inputs)
Register Name Address
Modicon
Address
Details
Force ON Input State 0 10001
0 = Input off (open contact)
1 = Input on (closed contact)
Force OFF Input State 1 10002
0 = Input off (open contact)
1 = Input on (closed contact)
Lock/Auto Input State 2 10003
0 = Input off (open contact)
1 = Input on (closed contact)
External Fault Input State 3 10004
0 = Input off (open contact)
1 = Input on (closed contact)
Running Status Relay State 4 10005
0 = Relay de-energised
1 = Relay energised
Heating Status Relay State 5 10006
0 = Relay de-energised
1 = Relay energised
Cooling Status Relay State 6 10007
0 = Relay de-energised
1 = Relay energised
Fault Relay State 7 10008
0 = Relay de-energised
1 = Relay energised
Comms Settings Switch State (DIP
switch 1-6)
8 10009
0 = Fixed 9600 baud, no parity (DIP Switch off)
1 = Software selectable settings (DIP Switch on)
Protocol Selection Switch State
(DIP switch 1-7)
9 10000
0 = Reserved (DIP Switch off)
1 = Modbus RTU (DIP Switch on)
Auto/Lock Mode Selection Switch
State (DIP switch 1-8)
10 10011
0 = Auto Mode selected (DIP Switch off)
1 = Lock Mode selected (DIP Switch on)
Deadband Enabled Switch State
(DIP switch 2-1)
11 10012
0 = Deadband Mode disabled (DIP Switch off)
1 = Deadband Mode enabled (DIP Switch on)
Setpoint Limiting Enabled Switch
State (DIP switch 2-2)
12 10013
0 = Setpoint Limiting disabled (DIP Switch off)
1 = Setpoint Limiting enabled (DIP Switch on)
Timeout Enabled Switch State (DIP
switch 2-3)
13 10014
0 = Timeout disabled (DIP Switch off)
1 = Timeout enabled (DIP Switch on)
Analogue Input Type Selection
Switch State (DIP switch 2-4)
14 10015
0 = Voltage input type selected (DIP Switch off)
1 = Resistance input type selected (DIP Switch on)
Page 41
12.4. Coils
Coils are read using function code 01 and written to using either function code 05 or 15. Function code 05 is used when
writing to a single coil register, function code 15 is used for writing to multiple coil registers in the same command.
Note the values of all Coil registers have corresponding Holding registers which can be used instead.
Coils (Digital Outputs)
Register Name Address
Modicon
Address
Details
Drive On/Off
(Note: Holding register address 7
can also be used to change the
Drive)
0 00001
0 = Drive OFF
1 = Drive ON
Page 42
Appendix A – Compatible Air-To-Air units
UK Models
M Series
MSZ-SF25/35/50VE
MSZ-GF60/71VE
MSZ-EF25/35/50VES/VEW/VEB
MSZ-FH25/35VE
MSZ-FD25/35VA
MSZ-GE22/25/35/50/60/71VA
MSZ-GC22/25/35VA
MSZ-GB50VA
MSZ-GA22/25/35/50/60/71VA
MFZ-KA25/35/50VA
Mr Slim
PCA-RP50/60/71/100/125/140KAQ
PEAD-RP35/50/60/71/100/125/140JAQ
PEAD-RP35/50/60/71/100/125/140EA/EA2
PEA-RP200/250GAQ
PKA-RP35/50HAL
PKA-RP60/71/100KAL
PLA-ZRP35/50/60/71/100/125/140BA/BA2
PLA-RP35/50/60/71/100/125/140BA/BA2/BA3
PLA-RP35/50/60/71/100/125/140AA/AA2
PSA-RP71/100/125/140KA
PSA-RP71/100/125/140GA
SEZ-KD25/35/50/60/71VAQ
SEZ-KA35/50/60/71VA
SLZ-KA25/35/50VAQ
SLZ-KA25/35/50VA
Models Not Supported:
MSZ-HJ25/35VA
MSZ-HC25/35VA/VAB
PCA-RP71/125HA/HAQ
PEA-RP400/500GAQ
Pleas e be sure
t
this ma
MI
T
MITSUBISHI EL
o put the c
nual befor
e
SUBIS
CTRIC UK, TRAVE
L
ontact add
handing i
t
HI ELE
C
LERS LANE, HATFI
ress/telep
h
t
to the cu
s
TRIC
U
ELD, HERTFORDSH
one numb
tomer.
IRE, AL10 8XB
er on
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