page 15
Figure 12: Air handling unit with MIXIT integration using few datapoints.
Figure 13: Air handling unit with MIXIT integration using more datapoints and read back for improved reliability and sequencing.
frost swit ch wit h m anual reset
_
+
ZONE
T
A
Out door air
Dischar ge air
pr eheat t em p
cont r oller
zone t em p
cont r oller
sequencing
and
defr ost
T
Z
T
O
Set st art / st op:
BO,1
Set point :
AO,0
T
A
Dam per rat io
on/ off,
set point ,
defrost
T
A
T
Z
T
A
reference
AH U con t r olle r
T
Z
reference
AHU
signal
split t er
Set st art / st op:
BO,1
Set point :
AO,0
signal available on fieldbus
analogue signal
int ernal variable
Tem perat ure cont rol
enabled:
BI ,1
q
air t em p
heat ing
coil pr eheat
and fr ost
T
F
T
S
T
R
Valve opening:
AI ,1 9
M I X I T
AI ,2 1
AI ,1 7
AI ,1 6
AI ,2 7
AI ,2 0
_
+
q
ZONE
T
A
Out door air
Dischar ge air
pr eheat t em p
cont r oller
air t em p
heat ing
zone t em p
cont r oller
coil pr eheat
and fr ost
sequencing
and
defr ost
T
Z
T
O
T
F
T
S
T
R
Set st art / st op:
BO,1
St art / st op read back:
BI ,2
Set point :
AO,0
Set point read back:
AI ,0
Set frost risk:
BO,4
Frost risk det ect ed:
BI ,7
T
A
Dam per rat io
on/ off,
set point ,
defrost
T
A
Valve opening:
AI ,1 9
T
Z
T
A
reference
AH U con t r olle r
T
Z
reference
AHU
signal
split t er
Tem perat ure cont rol
enabled:
BI ,1
M I X I T
signal available on fieldbus
ot her signal
int ernal variable
AI ,2 1
AI ,1 7
AI ,1 6
AI ,2 0
AI ,2 7
