Intesis
TM
INMBSMIT001I000
User’s Manual r22
EN
© HMS Industrial Networks S.L.U - All rights reserved
This information is subject to change without notice
URL https://www.intesis.com
11 / 20
4.2.3
Considerations on Temperature Registers
•
AC unit temperature setpoint (R/W)
(register 4
–
in Protocol address / register 5
–
in PLC address):
This is the adjustable temperature setpoint value that must be required by the User. This
register can be read (Modbus function 3 or 4) or written (Modbus functions 6 or 16). A
Remote Controller connected to the Mitsubishi indoor unit will report the same
temperature setpoint value as this register. This will apply when no AC unit
’
s external
reference temperature is provided from INMBSMIT001I000 (see details 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 Mitsubishi 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
Mitsubishi 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 us to provide an external temperature’s sensor from the Modbus
side. Mitsubishi indoor unit does not allow, on devices like INMBSMIT001I000, to provide
directly a 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 (e.g. from Modbus side), INMBSMIT001I000 applies the following
mechanism (only if “external temperature’s reference” is being used):
o
After a couple of values have been entered in the “AC unit external temperature’s
reference” (register 22/23) and
the
“AC unit temperature set point” (register
4/5), INMBSMIT001I000 calculates the corresponding temperature
’s
demand
(e.g.,
if a “temperature setpoint (register 4/5)” of
22ºC
, and an “external
temperature reference (register 22/23)” of
20ºC
are entered, INMBSMIT001I000
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), INMBSMIT001I000 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 INMBSMIT001I000
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 INMBSMIT001I000 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, when INMBSMIT001I000 receives
a new temperature´s value coming from the indoor unit of
25ºC
,
INMBSMIT001I000 will automatically adjust the temperature setpoint required of
the AC indoor unit to
25ºC + 2ºC = 27ºC
).