Intesis
TM
INMBSMID---I000
User’s Manual r
1.3 EN
© HMS Industrial Networks S.L.U - All rights reserved
This information is subject to change without notice
URL https://www.intesis.com
15 / 24
4.4
Considerations on Temperature Registers
The next information refers to INMBSMID001I000 and may not apply to INMBSMID004I000
/ INMBSMID008I000 /INMBSMID032I000.
•
AC unit temperature setpoint (R/W)
(register 4
–
in Protocol address / register 5
–
in PLC address):
This is the adjustable temperature setpoint value required by the user.
This register can be read (Modbus function 3 or 4) or written (Modbus functions 6 or
16). If present, a remote controller
connected to the Midea indoor unit will report the
same temperature setpoint value as this register, but only will happen when no AC
unit´s external reference is provided from INMBSMID001I000 (see detail for register
22/23 below).
•
AC unit temperature reference (R)
(register 5
–
in Protocol address / register 6
–
in PLC address):
This register reports the temperature that is currently used by the Midea indoor unit
as the reference of its own control loop. Depending on the configuration of the indoor
unit, this value can be the temperature reported by the sensor on the return path of
the Midea indoor unit or the sensor of its remote controller. It is a read-only register
(Modbus functions 3 or 4).
•
AC unit external temperature reference (Modbus) (R/W)
(register 22
–
in Protocol address / register 23
–
in PLC address):
This register allows to provide an external temperature’s
value from the Modbus
side. The Midea indoor unit does not allow to provide an external temperature to be
used as a reference of the control loop of the AC indoor unit. In order to overcome
this limitation and enable the usage of an external temperature sensor (i.e. from
Modbus side), INMBSMID001I000
applies the following mechanism (only if “external
temperature’s reference” is bein
g used):
o
After a couple of values have been entered in the “AC unit external
temperature’s reference” (register 22/23) and “AC unit temperature set point”
(register 4/5), INMBSMID001I000 is going to estimate the chosen
temperature differences
(e.g. if a “temperature setpoint (register 4/5)” of
22ºC
, and an “external temperature reference (register 22/23)” of
20ºC
are
entered, INMBSMID001I000 will assume that the user is demanding a
+2ºC
increase in temperature).
o
By knowing at any time the ambient temperature currently used by the indoor
unit to control its own operation (register 5/6), INMBSMID001I000 can
calculate the required temperature setpoint needed to apply the
decrease/increase on the real temperature and reach the temperature chosen
by the user (following the example above, if INMBSMID001I000 reads an
“ambient temperature” (register 5/6) of
24ºC
in the indoor unit, it will apply
a final setpoint of
24ºC + 2ºC = 26ºC
).
o
At this moment, each time that INMBSMID001I000 detects a change on the
ambient temperature reported by the indoor unit (register 5/6), it will also
change the required setpoint, in order to keep the temperature required by
the user at any time. If we follow the last example, if INMBSMID001I000
receives a new temperature´s value coming from the indoor unit of
25ºC
,
INMBSMID001I000 will automatically adjust the temperature setpoint
required of the AC indoor unit to
25ºC + 2ºC = 27ºC
).
