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
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4
Modbus Interface Specification
4.1
Modbus physical layer
INMBSMID---I000 implements a Modbus RTU (Slave) interface, to be connected to an EIA-
485 line. It performs an 8N2 communication (8 data bits, no parity and 2 stop bit) with
several available baud rates (2400 bps, 4800 bps, 9600 bps -default-, 19200 bps, 38400
bps, 57600 bps, 76800 bps and 115200 bps). It also supports 8N1 communication (8 data
bits, no parity and 1 stop bit).
4.2
Modbus Registers for INMBSMID001I000
All registers are
type “16
-
bit unsigned Holding Register”
and use the standard
ModBus big
endian
notation.
The indoor unit (IU) that is being controlled must have Unit Address
0
. This address needs to
be set in the AC unit.
4.2.1 Control and status registers
Register Address
(protocol address)
Register Address
(PLC address)
R/W Description
0
1
R/W
AC unit On/Off
▪
0: Off
▪
1: On
1
2
R/W
AC unit Mode
1
▪
0: Auto (Default value)
▪
1: Heat
▪
2: Dry
▪
3: Fan
▪
4: Cool
2
3
R/W
▪
0: Auto (Default value)
▪
1: SP1
▪
2: SP2
▪
3: SP3
3
4
R/W
▪
0: Off (Default value)
▪
10: Swing
4
5
R/W
AC unit Temperature setpoint
1,2,3
▪
-32678 (Initialization value)
▪
17..30 ºC (ºC/x10ºC)
▪
63..86 ºF
5
6
R
▪
-32678 (Initialization value)
▪
Ranges determined by the Manufacturer
of the AC indoor unit. (ºC/x10ºC/ºF)
6
7
R/W
Window Contact
▪
0: Closed (Default Value)
▪
1: Open
1
Available values will depend on the AC unit mode. Check the AC unit model functions in its User Manual to know the possible
values for this register.
2
Magnitude for this register can be adjusted to Celsius x 1ºC, Celsius x 10ºC (default) or Fahrenheit. See section 4.5 for more
information.
3
It is not possible turn the value shown in Fahrenheit to x10.
