Advanced Functions; Probes (Analogue Inputs) - Carel MPXPRO User Manual

This chapter examines the categories of parameters already described
in the chapter on basic functions, so as to explain the use of the
corresponding advanced parameters and control algorithms. In addition,
the parameters relating to the compressor are explained, all of which are
advanced level parameters.

6.1 Probes (analogue inputs)

For an introduction to the probe parameters, see paragraph 5.1. Below is
a description of the advanced parameters relating to the probes.
Type of probe, group 1 (parameter /P1)
Set the probes type S1, S2, S3. See the paragraph 5.1.
Par. Description
/P1 Type of probe, group 1 (S1...S3)
Type of probe, group 2 (parameter /P2)
Set the probes type S4 e S5. See the paragraph 4.3.
Type of probe, group 3 (parameter /P3)
Set the probe type S6. See the paragraph 4.3.
Type of probe, group 4 (parameter /P4)
Set the probe type S7. See the paragraph 5.1.
Par. Description
/P4 Type of probe, group 4 (S7)
Type of probe, group 5 (parameter /P5)
Par. Description
/P5 Type of probe, group 5 : serial probes (S8
to S11)
MPXPRO can also manage up to 4 serial probes, which are set directly
from the supervisor. These can be defi ned as temperature probes or
generic probes, according to the setting of parameter /P5.
/P5 Probe 8 Probe 9
0 T
1 G
2 T
3 G
4 T
5 G
6 T
7 G
8 T
9 G
10 T
11 G
12 T
13 G
14 T
15 G
Key: T = temperature probe, G = generic probe
Minimum and maximum value probe S6 and S7
(parameters /L6,/U6,/L7,/U7)
MPXPRO, as well as the common NTC, PTC and PT1000 probes, can
connect one of the following to inputs S6 and S7:
• one 0 to 5Vdc ratiometric probe (powered directly by the controller),
connected to the input S6 or to the input S7;
• one 4 to 20 mA active probe (not powered by the controller),
connected to input S7;

6. ADVANCED FUNCTIONS

Def Min Max UoM
0 0 3 -
Tab. 6.a.a
Def Min Max UoM
0 0 6 -
Tab. 6.a.b
Def Min Max UoM
0 0 15 -
Tab. 6.a.c
Probe 10 Probe 11
T T T
T T T
G T T
G T T
T G T
T G T
G G T
G G T
T T G
T T G
G T G
G T G
T G G
T G G
G G G
G G G
Tab. 6.a.d
• one 0 to 10 Vdc active probe (not powered by the controller),
connected to input S7.
These types of probes require defi nition of their range of measurement,
that is, the maximum value and minimum value of measurement are set,
using parameters /L6, /L7, /U6 and /U7.
Par. Description
/U6 Maximum value of probe 6
/L6 Minimum value of probe 6
/U7 Maximum value of probe 7
/L7 Minimum value of probe 7
Assign probe functions (parameters /Fd, /FE, /FF,
/FG, /FH, /FI, /FL, /FM, /Fn)
For parameters /Fd and /FE see paragraph 4.3.
As well as the outlet Sm, intake Sr and defrost probes Sd, MPXPRO also
features:
• defrost probe Sd2, used on the primary or secondary evaporator;
• auxiliary temperature probe 1;
• auxiliary temperature probe 2;
• ambient temperature probe;
• ambient humidity probe;
• glass temperature probe;
• dewpoint serial probe.
The ambient temperature is used by the algorithm to calculate the
dewpoint, together with the ambient humidity and glass temperature.
The value of the dewpoint can also be sent by the serial probe, for
example from the supervisor. See paragraph 6.3.
Par. Description
/Fd Assign superheated gas temperature probe
(tGS)
/FE Assign saturated evaporation pressure/
temperature (PEu/tEu)
/FF Assign defrost temperature probe 2 (Sd2)
See /FA
/FG Assign auxiliary temperature probe 1
(Saux1) See /FA
/FH Assign auxiliary temperature probe 2
(Saux2) See /FA
/FI Assign ambient temperature probe (SA)
See /FA
/FL Assign ambient humidity probe (SU) See
/FA
/FM Assign glass temperature probe (Svt) See
/FA
/Fn Assign dewpoint value to serial probe (Sdp)
0 = Func. disabled 3 = Serial probe S10
1 = Serial probe S8 4 = Serial probe S11
2 = Serial probe S9
Note: in models with built-in driver, the default values are /Fd=4
and /FE=6.
Calibration (parameters /c4,/c5,/c6,/c7,/cE)
Parameters /c4 to /c7 are used to correct the reading made by probes
S4 to S7 respectively. Serial probes S8 to S11 do not require calibration.
/cE calibrates the saturated evaporation temperature. Calibration is
performed before checking if the value is out-of-range, that is, MPXPRO
fi rst determines the values read by the probes, correcting them based on
the calibration parameters, then checks if these are outside of the range
specifi ed and where necessary generates a probe error.
Example: To decrease the temperature measured by probe S4 by 3°C, set
/c4 = -3.
41
ENG
Def Min Max UoM
9.3 /L6 160 barg, RH%
-1 -20 /U6 barg, RH%
9.3 /L7 160 barg, RH%
-1.0 -20 /U7 barg, RH%
Tab. 6.a.e
Def Min Max UoM
0 0 11
0 0 11
0 0 11
0 0 11
0 0 11
0 0 11
0 0 11
0 0 11
0 0 4
Tab. 6.a.f
MPXPRO - + 0300055EN rel. 1.1 30/08/10