HMS Intesis INMBSMID I000 Series, User Manual, Page: 16 / 24

Intesis TM INMBSMID---I000
User’s Manual r 1.3 EN
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This information is subject to change without notice
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o
In general, INMBSMID001I000 is constantly applying the “ Virtual
Temperature ” formula:
S
AC
= S
u
– ( T
u
– T
AC
)
Where:
S
AC
- setpoint value currently applied to the indoor unit
S
u
- setpoint value written at Modbus side (register 4/5)
T
u
- external temperature reference written at Modbus side (register 22/23)
T
AC
- ambient temperature that the indoor unit is using as the reference of
its own control loop (register 5/6)
When INMBSMID001I000 detects a change in any of the values of
{
S
u
, T
u
, T
AC
}, it will send the new setpoint (
S
AC
) to the indoor unit.
o
After the startup, the value for “external temperature’s reference” (register
22/23) has a value -32768 (0x8000). This value means that no external
temperature reference is being provided through INMBSMID001I000. In this
scenario, the setpoint value shown in register 4/5 will always be the same as
the current setpoint value of the indoor unit. AC indoor unit will use its own
return path temperature sensor as reference for its control loop.
o
When the mechanism of “ Virtual Temperature ” is applied
.
The temperature
setpoint’s value shown by the Remote Controller from Midea connected to the
indoor unit shall show a different value from the value shown in register 4/5.
Instead it shall show the calculated Virtual Setpoint.
• AC Real temperature setpoint (R)
(register 23 – In Protocol address / register 24 – in PLC address) :
As detailed on the previous point, the real temperature setpoint in the indoor unit
and the temperature setpoint requested from INMBSMID001I000 might differ (when
a value in register 22/23
– “external temperature reference” is entered). This
register always informs about the current temperature setpoint, used by the indoor
unit
– this is the actual setpoint that will be shown by an additional remote controller
if present.
Moreover, notice that temperature’s values of all these three registers are expressed
according to the temperature’s
format configured through its onboard DIP-Switches. The
following formats are possible:
• Celsius value : Value in Modbus register is the temperature value in Celsius (i.e.
a value “22” in the Modbus register must be interpreted as 22ºC).
• Decicelsius value : Value in Modbus register is the temperature value in
decicelsius (i.e. a value “220” in the Modbus register must be interpreted as
22.0ºC).
• Fahrenheit value : Value in Modbus register is the temperature value in
Fahrenheit (i.e. a value “72” in the Modbus register must be interpreted as 72ºF
(~22ºC).