Emerson Dixell XR75CX Series User manual

XR75CX Digital Controller for Medium-Low
Temperature Refrigeration Applications
Installation and Operation Manual
026-1210 Rev 4

Emerson
1065 Big Shanty Road NW, Suite 100
Kennesaw, GA 30144 USA
770-425-2724 • www.emerson.com

Table of Contents • i
Table of Contents
1 INTRODUCTION.......................................................................................................................................................... 1
1.1. GENERAL WARNING ..................................................................................................................................................... 1
2 OVERVIEW ................................................................................................................................................................... 1
2.1. GENERAL DESCRIPTION................................................................................................................................................ 1
2.2. ORDERING CODE ......................................................................................................................................................... 1
3 CONTROLLING LOADS ............................................................................................................................................ 2
3.1. COMPRESSOR ................................................................................................................................................................ 2
3.2. DEFROST ....................................................................................................................................................................... 2
3.3. CONTROL OF EVAPORATOR FANS ................................................................................................................................ 2
3.3.1. Forced Activation of Fans..................................................................................................................................... 2
3.3.2. Cyclical Activation of the Fans With Compressor Off.......................................................................................... 2
3.4. LIGHT RELAY CONFIGURATION (PAR OA2; TERMINALS 1-2)..................................................................................... 3
3.4.1. Light Relay............................................................................................................................................................ 3
3.4.2. Auxiliary Relay – oA2=AUS................................................................................................................................. 3
3.4.3. On/Off Relay (oA2=onF)...................................................................................................................................... 3
3.4.4. Neutral Zone Regulation...................................................................................................................................... 3
3.4.5. Alarm Relay........................................................................................................................................................... 3
3.4.6. Night Blind Management During Energy Saving Cycles...................................................................................... 3
4 FRONT PANEL COMMANDS.................................................................................................................................... 4
4.1. KEYS AND FUNCTIONS ................................................................................................................................................. 4
4.2. USE OF LEDS............................................................................................................................................................... 4
5 MAX AND MIN TEMPERATURE MEMORIZATION........................................................................................... 5
5.1. HOW TO SEE THE MIN TEMPERATURE ........................................................................................................................ 5
5.2. HOW TO SEE THE MAX TEMPERATURE....................................................................................................................... 5
5.3. HOW TO RESET THE MAX AND MIN TEMPERATURE RECORDED ................................................................................. 5
6 MAIN FUNCTIONS ...................................................................................................................................................... 6
6.1. HOW TO SEE THE SETPOINT ......................................................................................................................................... 6
6.2. HOW TO CHANGE THE SETPOINT.................................................................................................................................. 6
6.3. HOW TO START A MANUAL DEFROST.......................................................................................................................... 6
6.4. HOW TO CHANGE A PARAMETER VALUE..................................................................................................................... 6
6.5. THE HIDDEN MENU ...................................................................................................................................................... 6
6.5.1. How to Enter the Hidden Menu ............................................................................................................................ 6
6.5.2. How to Move a Parameter From the Hidden Menu To the First Level and Vice Versa ...................................... 7
6.6. HOW TO ASSIGN A MODBUS ADDRESS ..................................................................................................................... 7
6.7. HOW TO LOCK THE KEYBOARD ................................................................................................................................... 7
6.8. TO UNLOCK THE KEYBOARD ....................................................................................................................................... 7
6.9. THE CONTINUOUS CYCLE............................................................................................................................................. 7
6.10. THE ON/OFF FUNCTION ............................................................................................................................................ 7
7 PARAMETERS ............................................................................................................................................................. 8
8 DIGITAL INPUTS....................................................................................................................................................... 13
8.1. GENERIC ALARM (I2F=EAL) ..................................................................................................................................... 13
8.2. SERIOUS ALARM MODE (I2F=BAL) ........................................................................................................................... 13

ii • XR75CX I&O Manual 026-1210 Rev 4
8.3. PRESSURE SWITCH (I2F=PAL) ................................................................................................................................... 13
8.4. DOOR SWITCH INPUT (I1F OR I2F=DOR) .................................................................................................................... 13
8.5. START DEFROST (I1F OR I2F=DEF)............................................................................................................................ 13
8.6. SWITCH THE AUXILIARY RELAY (I2F=AUS) ............................................................................................................. 13
8.7. INVERSION OF THE KIND OF ACTION: HEATING - COOLING (I2F=HTR) .................................................................... 13
8.8. ENERGY SAVING (I2F=ES) ......................................................................................................................................... 13
8.9. ON - OFF FUNCTION (I2F=ONF)................................................................................................................................ 13
8.10. DIGITAL INPUTS POLARITY....................................................................................................................................... 14
9 RS485 SERIAL LINE (FOR MONITORING SYSTEMS)...................................................................................... 15
10 X-REP OUTPUT (OPTIONAL)............................................................................................................................... 15
11 INSTALLATION AND MOUNTING ..................................................................................................................... 16
12 ELECTRICAL CONNECTIONS............................................................................................................................. 16
12.1. PROBE CONNECTION ................................................................................................................................................. 16
13 HOW TO USE THE HOT KEY ............................................................................................................................... 17
13.1. HOW TO PROGRAM A HOT KEY FROM THE DEVICE (UPLOAD) ............................................................................... 17
13.2. HOW TO PROGRAM THE DEVICE USING A HOT KEY (DOWNLOAD)......................................................................... 17
14 ALARM SIGNALS ................................................................................................................................................... 18
14.1. SILENCING BUZZER/ALARM RELAY OUTPUT ........................................................................................................... 18
14.2. ALARM RECOVERY ................................................................................................................................................... 18
14.3. OTHER MESSAGES .................................................................................................................................................... 18
15 SPECIFICATIONS.................................................................................................................................................... 19
16 CONNECTIONS ........................................................................................................................................................ 21
17 E2 MODBUS NETWORK WIRING ....................................................................................................................... 22
18 ECT MODBUS NETWORKING TO E2S............................................................................................................... 23
18.1. COM PORT ASSOCIATIONS - E2 VERSIONS 3.XX AND BELOW ................................................................................ 23
18.2. COM PORT ASSOCIATIONS - E2 VERSIONS 4.2 AND ABOVE ................................................................................... 23
18.3. E2 SETUP OF DEVICES .............................................................................................................................................. 24
18.3.1. Set Up Network Ports........................................................................................................................................ 24
18.3.2. Add and Connect the Device............................................................................................................................. 24
18.4. WIRING TYPES .......................................................................................................................................................... 25
18.5. MODBUS TERMINATION BLOCKS ........................................................................................................................... 26
19 DEFAULT SETTING VALUES .............................................................................................................................. 27
APPENDIX A - ALTERNATE MODBUS COM WIRING METHOD FOR E2, XR, XM, AND XEV DEVICES 31

General Warning Introduction • 1
1 Introduction
1.1. General Warning
Please read the following safety precautions and warnings
before using this manual:
2Overview
2.1. General Description
Model XR75CX (32 mm x 74 mm) is a microprocessor
based controller, suitable for applications on medium or
low temperature ventilated refrigeration units. It has four
(4) relay outputs to control compressor, fan, and defrost,
which can be either electrical or reverse cycle (hot gas) and
light (configurable).
It can also have up to four (4) NTC (EU or US type) probe
inputs. The first probe is used for temperature control. The
second probe is used to control the defrost termination 
temperature at the evaporator. One of the two (2) digital 
inputs can operate as a third temperature probe. The fourth
probe is used to control the condenser temperature (for 
condenser alarm 
management) or to display a temperature value. Set the
PbC parameter to CtC to support standard CPC 
temperature sensors (factory default).
The RS-485 serial output enables the unit to be connected
to a network line that is MODBUS-RTU compatible, such
as the monitoring units of XWEB family. The Hot Key 
receptacle allows the controller to be programmed by
means of the Hot Key programming keyboard.
The controller is fully configurable through special 
parameters that can be easily programmed through the 
keyboard.
2.2. Ordering Code
CAUTION!
• This manual is part of the product and
should be kept near the device for easy and
quick reference.
• The device should not be used for purposes

different from those described in this manual. It 
cannot be used as a safety device.
• Check the application limits before proceeding.
SAFETY PRECAUTIONS AND 
WARNINGS!
• Check that the supply voltage is correct
before connecting the device.
• Do not expose to water or moisture: use the

controller only within the operating limits and avoid
sudden temperature changes with high atmospheric
humidity to prevent condensation from forming.
• Warning! Disconnect all electrical connections
before performing any kind of maintenance.
• Fit the probe where it is not accessible by the end
user. The device must not be opened.
• In case of failure or faulty operation, send the
device back to the distributor or to Emerson (see
address) with a detailed description of the fault.
• Verify the maximum current that can be applied
to each relay (see Section 15, Specifications).
• Ensure that the wires for probes, loads, and the
power supply are separated and far enough from each
other without crossing or intertwining.
• In case of applications in industrial

environments, the use of main filters (our mod. FT1)
in parallel with inductive loads could be useful.
Device
Name Dixell Code Emerson Code
XR75CX -
110VAC
XR75CX-4C6F3B -
X0LG3OEUB4NA-000 318-6030
XR75CX -
230VAC
XR75CX-5C6F3B -
X0LG3OEUB5NA-000 318-6031
Table 2-1 - Product Ordering Code

2 • XR75CX I&O Manual 026-1210 Rev 4
3 Controlling Loads
3.1. Compressor
The regulation is performed according to the temperature
measured by the thermostat probe with a positive 
differential (HY) from the setpoint: if the temperature 
increases and reaches setpoint plus the differential, the
compressor is started and then turned OFF when the 
temperature reaches the setpoint value again.
In case of a fault in the thermostat probe, the start and stop
of the compressor are timed through parameters Con and
CoF.
3.2. Defrost
Two defrost modes are available through the tdF 
parameter: defrost through electrical heater (tdF=EL) and
hot gas defrost (tdF=in).
•EdF=in, the defrost is made every idF time (the
standard method for the controller)
Other parameters are used to control defrost cycles: its
maximum duration (MdF) and two defrost modes: timed or
controlled by the evaporator’s probe (P2P).
At the end of defrost dripping time is started, its 
duration is set in the Fdt parameter. With Fdt=0, the 
dripping time is disabled.
3.3. Control of Evaporator
Fans
The fan control mode is selected by means of the FnC 
parameter:
•FnC = C_n: fans will switch ON and OFF with the
compressor and not run during defrost.
•FnC = O_n: fans will run even if the compressor is
OFF, and not run during defrost.
After defrost, there is a timed fan delay allowing for
drip time, set by means of the Fnd parameter.
•FnC = C_y: fans will switch ON and OFF with the
compressor and run during defrost.
•FnC = O_y: fans will run continuously during 
defrost also.
An additional parameter called FSt provides the 
setting of temperature, detected by the evaporator probe,
above which the fans are always OFF. This is used to make
sure that air is circulated only if this temperature is lower
than set in FSt.
3.3.1. Forced Activation of Fans
Managed by the Fct parameter, this function is 
designed to avoid short cycles of fans that could occur
when the controller is switched ON or after a defrost, when
the room air warms the evaporator.
How it works: If the temperature difference between the
evaporator probe and the room probe is higher than the Fct
parameter value, the fans will be switched ON. When Fct
= 0, the function will be 
disabled.
3.3.2. Cyclical Activation of the Fans
With Compressor Off
When FnC = C-n or C-y (fans are working in parallel with
the compressor), by means of the Fon and FoF parameters,
the fans can carry out ON and OFF cycles even if the 
compressor is switched OFF. When the compressor is
stopped, the fans will continue to work for the Fon time.
With Fon = 0, the fans always remain OFF when the 
compressor is OFF.
3.4. Light Relay
Configuration (PAR
oA2; Terminals 1-2)
The functioning of the auxiliary relay (terminals 
1-2) can be set by the oA2 parameter, according to the kind
of application needed. Possible settings are as follows:
Figure 3-1 - Compressor Temperature Regulation

Light Relay Configuration (PAR oA2; Terminals 1-2) Controlling Loads • 3
3.4.1. Light Relay
When oA2 = Lig, the relay 1-2 operates as a light.
3.4.2. Auxiliary Relay — oA2=AUS
a. Relay Activation By Digital Input 2 (oA2 = AUS,
i2F = AUS)
When oA2 = AUS and i2F = AUS, the relay 1-2 is switched
ON and OFF by the digital input.
b. Auxiliary Thermostat
An anti-condensing heater with the possibility of switching
it ON and OFF with the keyboard.
Parameters Involved
•ACH - The kind of regulation for the auxiliary relay:
Ht: heating; CL: cooling
•SAA - Setpoint for auxiliary relay
•SHY - Differential for auxiliary relay
•ArP - Probe for auxiliary relay
•Sdd - Auxiliary output OFF during defrost
The differential is set by the SHY parameter.
3.4.3. On/Off Relay (oA2=onF)
When oA2 = onF, the relay is activated when the controller
is turned ON and de-activated when the controller is turned
OFF.
3.4.4. Neutral Zone Regulation
When oA2 = db, the relay 1-2 can control a heater 
element to perform a neutral zone action.
•oA2 cut in = SET-HY
•oA2 cut out = SET
3.4.5. Alarm Relay
When oA2 = ALr, the relay 1-2 operates as an alarm relay.
It is activated every time an alarm occurs. Its status depends
on the tbA parameter: if tbA = y, the relay is silenced by
pressing any key. If tbA = n, the alarm relay remains ON
until the alarm condition recovers.
3.4.6. Night Blind Management
During Energy Saving Cycles
With oA2 = HES, the relay 1-2 operates to manage the
night blind: the relay is powered when the energy saving
cycle is activated by a digital input, front panel button.
NOTE: Set oA2 =AUS and ArP= nP (no probe
for auxiliary output). In this case, the relay 1-2
can be activated only by the digital input with
i1F or i2F = AUS.

4 • XR75CX I&O Manual 026-1210 Rev 4
4 Front Panel
Commands
4.1. Keys and Functions
Table 4-1 shows the keys that are found on the front panel
of the XR75CX controller and their corresponding 
functions:
4.2. Use of LEDS
Each LED function is described in Table 4-2:
Figure 4-1 - XR75CX Front Panel
Key Function
Press to display target setpoint, to select a
parameter in programming mode, or to
confirm an operation
Starts a manual defrost
Press the UP arrow key to see the MAX
stored temperature, to browse the
parameter codes in programming mode,
or to increase the displayed temperature
value.
Press the DOWN arrow key to see the
MIN temperature, to browse the
parameter codes in programming mode,
or to decrease the displayed temperature
value.
Switches the device ON and OFF, if 
onF = oFF
Switches the light ON and OFF, if oA1 =
Lig
Table 4-1 - XR75CX Front Panel Keys and Functions
Locks/Unlocks the keyboard
To enter programming mode
Returns to room temperature display
LED Mode Function
ON Compressor enabled
Flashing Anti-short cycle delay enabled
ON Defrost enabled
Flashing Drip time in progress
ON Fans enabled
Flashing Fans delay after defrost in
progress.
ON An alarm is occurring
ON Continuous cycle is running
ON Energy saving enabled
ON Light ON
ON Auxiliary relay ON
ON Measurement unit
Flashing Programming phase
Table 4-2 - LEDs
Table 4-1 - XR75CX Front Panel Keys and Functions

How to See the MIN Temperature Max and Min Temperature Memorization • 5
5 Max and Min
Temperature
Memorization
5.1. How to See the MIN
Temperature
1. Press and release the DOWN button.
2. The Lo message will be displayed followed
by the minimum temperature recorded.
3. By pressing the DOWN button again or by
waiting five seconds, the normal display will
be restored.
5.2. How to See the MAX
Temperature
1. Press and release the UP button.
2. The Hi message will be displayed followed
by the maximum temperature recorded.
3. By pressing the UP button again or by 
waiting 5 seconds, the normal display will be
restored.
5.3. How to Reset the Max
and Min Temperature
Recorded
1. Press and hold the SET button for more than
3 seconds while the max or min temperature
is displayed (rSt message will be displayed).
2. After confirming the operation, the rSt 
message will start blinking and then the 
normal temperature will be displayed.

6 • XR75CX I&O Manual 026-1210 Rev 4
6 Main Functions
6.1. How to See the
Setpoint
1.Press and immediately release the
SET key: the display will show the
setpoint value.
2. Press and immediately release the SET key or
wait for 5 seconds to display the probe value
again.
6.2. How to Change the
Setpoint
1. Press and hold the SET button for more than
2 seconds to change the setpoint value.
2. The value of the setpoint will be displayed
and the °C or °F LED will start blinking.
3. To change the setpoint value, press the UP or
DOWN buttons within 10 seconds.
4. To memorize the new setpoint value, press
the SET key again or wait 10 seconds.
6.3. How to Start a Manual
Defrost
Press and hold the DEF key for more
than 2 seconds and a manual defrost
will start.
6.4. How to Change a
Parameter Value
To change a parameter value, follow these steps:
1. Enter the Programming mode by pressing the
SET + DOWN buttons for 3 seconds (the °C
or °F LED will start blinking).
2. Select the required parameter. Press the SET
button to display its value.
3. Use the UP or DOWN buttons to change its
value.
4. Press SET to store the new value and move to
the next parameter.
To exit: Press the SET + UP buttons or wait 15 seconds
without pressing a key.
6.5. The Hidden Menu
The hidden menu includes all the parameters of the 
controller.
6.5.1. How to Enter the Hidden
Menu
1. Enter the Programming mode by pressing the
SET + DOWN buttons for three (3) seconds
(the °C or °F LED will start blinking).
2. Release the buttons and then push the SET +
DOWN buttons for more than seven (7) 
seconds. The Pr2 label will be displayed 
immediately followed by the HY parameter:
You can now browse the Hidden Menu.
3. Select the required parameter.
4. Press the SET button to display its value.
5. Use the UP or DOWN buttons to change its
value.
6. Press SET to store the new value and move to
the next parameter.
To exit: Press SET + DOWN or wait 15 seconds without
pressing a key.
NOTE: The set value is stored even when the
time-out expires and ends the procedure.
NOTE:If no parameteris presentin Pr1 menu,
after three (3) seconds the noP message is

displayed. Keep the keys pressed until the Pr2
message is displayed.
NOTE: The set value is stored even when the
time-out expires and ends the procedure.

How to Assign a MODBUS Address Main Functions • 7
6.5.2. How to Move a Parameter
From the Hidden Menu To the
First Level and Vice Versa
Each parameter present in the Hidden Menu (Pr2) can be
moved into the user level (Pr1) by pressing SET + DOWN
buttons. If a parameter is part of the user level, when it 
appears in the Hidden Menu, the decimal point will be 
illuminated.
6.6. How to Assign a
MODBUS Address
1. Follow steps 1 and 2 of Section 6.5.1., How
to Enter the Hidden Menu to access the 
Hidden Menu.
2. Select the Adr parameter.
3. Press SET to select.
4. Choose the address number using the buttons
and press SET again to save.
5. Press SET and UP buttons to exit.
Note that devices cannot have duplicate addresses on the
network. Assigning MODBUS addresses prior to 
terminating the network and leaving the address of device
1 as unused until the network is connected can prevent 
duplicate addressing network issues.
6.7. How to Lock the
Keyboard
1. Keep the UP + DOWN buttons pressed for
more than 3 seconds.
2. The PoF message will be displayed and the
keyboard will be locked. At this point it will
be possible to see the setpoint or the MAX or
Min temperature stored only.
3. If a button is pressed for more than 3 seconds
the PoF message will be displayed.
6.8. To Unlock the
Keyboard
Press and hold the UP and DOWN buttons for more than 3
seconds until the Pon message displays.
6.9. The Continuous Cycle
When a defrost is not in progress, it can be activated by
pressing and holding the UP button for about 3 seconds.
The compressor operates to maintain the CCS setpoint for
the time set through the CCt parameter. The cycle can be
terminated before the end of the set time using the same 
activation button (UP button for 3 seconds).
6.10.The ON/OFF Function
When onF = oFF, pressing the ON/OFF key
will switch OFF the controller. The OFF 
message is displayed. In this configuration, the
regulation is disabled.
To switch the controller ON, press the ON/
OFF key again.
WARNING! Loads connected to the normally
closed contacts of the relays are always

supplied and under voltage (powered up), even
if the device is in stand-by mode.

8 • XR75CX I&O Manual 026-1210 Rev 4
7 Parameters
Code Parameter Function
REGULATION
HY Differential
(0.1 to 25.5°C; 1 to 45°F) Intervention differential for setpoint.
Compressor Cut IN is Set Point + differential (HY). Compressor
Cut OUT is when the temperature reaches the setpoint.
LS Minimum setpoint (-50°C to SET; -58°F to SET) Sets the minimum value for the
setpoint.
US Maximum setpoint (SET to 110°C; SET to 230°F) Sets the maximum value for
setpoint.
ot Thermostat probe calibration (-12.0 to 12.0°C; -21 to 21°F) Allows to adjust possible offset of
the thermostat probe.
P2P Evaporator probe presence (n; Y) n = not present, the defrost stops by time; Y = present, the
defrost stops by temperature.
oE Evaporator probe calibration (-12.0 to 12.0°C; -21 to 21°F) Allows to adjust possible offset of
the evaporator probe.
P3P Third probe presence (P3) (n; Y) n = not present, the terminals 18-20 operate as digital
input; Y = present, the terminals 18-20 operate as third probe.
o3 Third probe calibration (P3) (-12.0 to 12.0°C; -21 to 21°F) Allows to adjust possible offset of
the third probe.
P4P Fourth probe presence (n; Y) n = Not present; Y = present
o4 Fourth probe calibration (-12.0 to 12.0°C; -21 to 21°F) Allows to adjust possible offset of
the fourth probe.
odS Outputs activation delay at start up
(0 to 255min) This function is enabled at the initial start up of
the instrument and inhibits any output activation for the period
of time set in the parameter.
AC Anti-short cycle delay (0 to 50min) Minimum interval between the compressor stop
and the following restart.
rtr Percentage of the second and first
probe for regulation
(0 to 100; 100=P1, 0=P2) Allows to set the regulation according
to the percentage of the first and second probe, as for the
following formula (rtr(P1-P2)/100 + P2).
CCt Compressor ON time during
continuous cycle
(0.0 to 24h00min, res. 10min) Allows to set the length of the
continuous cycle. Compressor stays ON without interruption
during CCt time. This is useful, for instance, when the room is
filled with new products.
CCS Setpoint for continuous cycle (-50 to 110°C; (-58 to 230°F) Sets the setpoint used during the
continuous cycle.
Con Compressor ON time with faulty
probe
(0 to 255min) Time during which the compressor is active in
case of faulty thermostat probe. With Con=0 compressor is
always OFF.
CoF Compressor OFF time with faulty
probe
(0 to 255min) Time during which the compressor is OFF in case
of faulty thermostat probe. With CoF=0 compressor is always
active.
DISPLAY
Table 7-1 - List of Parameters

The ON/OFF Function Parameters • 9
CF Temperature measurement unit
(°C; °F) °C = Celsius; °F = Fahrenheit.
CAUTION: When the measurement unit is changed the SET
point and the values of the parameters HY, LS, US, ot, ALU and
ALL have to be checked and modified (if necessary).
rES Resolution (for °C) (in=1°C; dE=0.1°C) Allows decimal point display.
Lod Instrument display
(P1; P2, P3, P4, SET, dtr) Selects which probe is displayed by
the instrument. P1 = Thermostat probe; P2 = Evaporator probe;
P3 = Third probe (only for model with this option enabled); P4
= Fourth probe, SET = setpoint; dtr = percentage of
visualization.
rEd X-REP display (optional)
(P1; P2, P3, P4, SET, dtr) Selects which probe is displayed by
X- REP. P1 = Thermostat probe; P2 = Evaporator probe; P3 =
Third probe (only for model with this option enabled); P4 =
Fourth probe, SET = setpoint; dtr = percentage of visualization.
dLY Display delay (0 to 20min00s; res. 10s) When the temperature increases, the
display is updated of 1°C or 1°F after this time.
dtr Percentage of the second and first
probe for visualization when Lod=dtr
(0 to 99; 100=P1, 0=P2) If Lod=dtr, it allows to set the
visualization according to the percentage of the first and second
probe, as for the following formula (dtr(P1-P2)/100 + P2).
DEFROST
tdF Defrost type (EL; in) EL = electrical heater; in = hot gas
dFP Probe selection for defrost termination
(nP; P1; P2; P3; P4) nP = no probe; P1 =thermostat probe; P2 =
evaporator probe; P3 =configurable probe; P4 = Probe on Hot
Key plug
dtE Defrost termination temperature
(-50 to 50°C; -58 to 122°F) (enabled only when EdF=Pb) Sets
the temperature measured by the evaporator probe, which
causes the end of defrost.
idF Interval between defrost cycles (0 to 120hours) Determines the interval of time between two
defrost cycles.
MdF (Maximum) length for defrost
(0 to 255min) When P2P=n, (not evaporator probe: timed
defrost) it sets the defrost duration. When P2P=Y (defrost end
based on temperature) it sets the maximum length for defrost.
dSd Start defrost delay (0 to 99min) This is useful when different defrost start times are
necessary to avoid overloading the plant.
dFd Temperature displayed during defrost (rt; it; SEt; dEF) rt = real temperature; it = temperature at defrost
start; SEt = setpoint; dEF = “dEF” label.
dAd MAX display delay after defrost (0 to 255min) Sets the maximum time between the end of
defrost and the restarting of the real room temperature display.
Fdt Drip time
(0 to 120min) Time interval between reaching defrost
termination temperature and the restoring of the control’s
normal operation. This time allows the evaporator to eliminate
water drops that might have formed due to defrost.
dPo First defrost after start-up (n; Y) n = after the idF time, Y = immediately
dAF Defrost delay after continuous cycle (0.0 to 24h00min, res. 10min) Time interval between the end of
the fast freezing cycle and the following defrost related to it.
FANS
Code Parameter Function
Table 7-1 - List of Parameters

10 • XR75CX I&O Manual 026-1210 Rev 4
FnC Fans operating mode
(C-n; o-n; C-Y; o-Y) C-n = runs with the compressor, OFF
during defrost; o-n = continuous mode, OFF during defrost; C-
Y = runs with the compressor, ON during defrost; o-Y =
continuous mode, ON during defrost.
Fnd Fans delay after defrost (0 to 255min) Interval between end of defrost and evaporator
fans start.
Fct Temperature differential to avoid fan
short cycles
(0 to 59°C; 0 to 90°F) (N.B.: if Fct=0 function disabled) If the
difference of temperature between the evaporator and the room
probes is higher than Fct value, the fans will be switched ON.
FSt Fans stop temperature (-50 to 50°C; -58 to 122°F) Setting of temperature, detected by
evaporator probe, above which fans are always OFF.
Fon Fan ON time
(0 to 15min) With FnC=C_n or C_Y, (fan activated in parallel
with compressor) it sets the evaporator fan ON cycling time
when the compressor is OFF. With Fon=0 and FoF≠0 the fan
are always OFF, with Fon=0 and FoF=0 the fan are always
OFF.
FoF Fan OFF time
(0 to 15min)
With FnC=C_n or C_Y, (fan activated in parallel with
compressor) it sets the evaporator fan OFF cycling time when
the compressor is OFF.
With Fon=0 and FoF≠0 the fan are always OFF, with Fon=0
and FoF=0 the fan are always OFF.
FAP Probe selection for fan management
(nP; P1; P2; P3; P4) nP = no probe; P1 =thermostat probe; P2 =
evaporator probe; P3 =configurable probe; P4 = Probe on Hot
Key plug.
AUXILIARY THERMOSTAT CONFIGURATION (terms. 1-2) - oA2 = AUS
ACH Kind of regulation for auxiliary relay (Ht; CL) Ht = heating; CL = cooling
SAA Set Point for auxiliary relay (-50 to 110.0°C; -58 to 230°F) It defines the room temperature
setpoint to switch auxiliary relay.
SHY Differential for auxiliary output
(0.1 to 25.5°C; 1 to 45°F) Intervention differential for auxiliary
output setpoint.
ACH=CL, AUX Cut in is [SAA+SHY]; AUX Cut out is SAA.
ACH=Ht, AUX Cut in is [SAA–SHY]; AUX Cut out is SAA.
ArP Probe selection for auxiliary
(nP; P1; P2; P3; P4) nP = no probe, the auxiliary relay is
switched only by the digital input; P1 = Probe 1 (Thermostat
probe); P2 = Probe 2 (evaporator probe); P3 = Probe 3 (display
probe); P4 = Probe 4
Sdd Auxiliary relay OFF during defrost (n; Y) n = the auxiliary relay operates during defrost; Y = the
auxiliary relay is switched OFF during defrost
ALARMS
ALP Probe selection for alarm
(nP; P1; P2; P3; P4) nP = no probe, the temperature alarms are
disabled; P1 = Probe 1 (Thermostat probe); P2 = Probe 2
(evaporator probe); P3 = Probe 3 (display probe); P4 = Fourth
probe
ALC Temperature alarms configuration
(Ab; rE) Ab = absolute temperature, alarm temperature is given
by the ALL or ALU values. rE = temperature alarms are
referred to the setpoint. Temperature alarm is enabled when the
temperature exceeds the [SET+ALU] or [SET-ALL] values.
Code Parameter Function
Table 7-1 - List of Parameters

The ON/OFF Function Parameters • 11
ALU MAXIMUM temperature alarm (ALL to 110°C; ALL to 230°F) When this temperature is
reached the alarm is enabled, after the ALd delay time.
ALL Minimum temperature alarm (-50°C to ALU; -58 to ALU) When this temperature is reached
the alarm is enabled, after the ALd delay time.
AFH Differential for temperature alarm
recovery
(0.1 to 25.5°C; 1 to 45°F) Intervention differential for recovery
of temperature alarm
ALd Temperature alarm delay (0 to 255 min) Time interval between the detection of an alarm
condition and alarm signaling.
dAo Exclusion of temperature alarm at
start-up
(0.0 to 24h00min, res. 10min) Time interval between the
detection of the temperature alarm condition after instrument
power ON and alarm signaling.
CONDENSER TEMPERATURE ALARM
AP2 Probe selection for temperature alarm
of condenser
(nP; P1; P2; P3; P4) nP = no probe; P1 =thermostat probe; P2 =
evaporator probe; P3 =configurable probe; P4 = Probe on Hot
Key plug
AL2 Low temperature alarm of condenser (-50 to 110°C; -58 to 230°F) When this temperature is reached
the LA2 alarm is signalled, possibly after the Ad2 delay.
Au2 High temperature alarm of condenser (-50 to 110°C; -58 to 230°F) When this temperature is reached
the HA2 alarm is signalled, possibly after the Ad2 delay.
AH2 Differential for temperature condenser
alarm recovery (0.1 to 25.5°C; 1 to 45°F)
Ad2 Condenser temperature alarm delay (0 to 255 min) Time interval between the detection of the
condenser alarm condition and alarm signaling.
dA2 Condenser temperature alarm
exclusion at start up (0.0 to 24h00min, res. 10min)
bLL Compressor OFF with low
temperature alarm of condenser
(n; Y) n = no: compressor keeps on working; Y = yes,
compressor is switched OFF until the alarm is present, in any
case regulation restarts after AC time at minimum.
AC2 Compressor OFF with high
temperature alarm of condenser
(n; Y) n = no: compressor keeps on working; Y = yes,
compressor is switched OFF until the alarm is present, in any
case regulation restarts after AC time at minimum.
AUXILIARY RELAY
tbA Alarm relay silencing (with oA2
=ALr)
(n; Y) n = silencing disabled: alarm relay stays ON until alarm
condition lasts; Y =silencing enabled: alarm relay is switched
OFF by pressing a key during an alarm.
oA2 Second relay configuration (1-2)
(dEF; FAn; ALr; LiG; AUS; onF; db; CP2; dEF2; HES) dEF =
defrost; FAn = do not select it; ALr = alarm; LiG = light; AUS
= Auxiliary relay; onF = always ON with instrument ON; db =
neutral zone; CP2 = do not select it; dEF2 = do not select it;
HES = night blind
AoP Alarm relay polarity
(CL; oP) it set if the alarm relay is open or closed when an alarm
occurs. CL = terminals 1-2 closed during an alarm; oP =
terminals 1-2 open during an alarm.
DIGITAL INPUTS
i1P Digital input polarity (18-20) (oP; CL) oP = the digital input is activated by opening the
contact; CL = the digital input is activated by closing the contact
Code Parameter Function
Table 7-1 - List of Parameters

12 • XR75CX I&O Manual 026-1210 Rev 4
i1F Digital input configuration (18-20) (dor; dEF) dor = door switch function; dEF = activation of a
defrost cycle
i2P Second digital input polarity (18-19) (oP; CL) oP = the digital input is activated by opening the
contact; CL = the digital input is activated by closing the contact
i2F Second digital input configuration
(18-19)
(EAL; bAL; PAL; dor; dEF; ES; AUS; Htr; FAn; HdF; onF)
EAL = external alarm: “EA” message is displayed; bAL =
serious alarm “CA” message is displayed; PAL = pressure
switch alarm, “CA” message is displayed; dor = door switch
function; dEF = activation of a defrost cycle; ES = energy
saving; AUS = auxiliary relay activation with oA2=AUS; Htr =
type of inverting action (cooling or heating); FAn = fan; onF =
to switch the controller OFF
did Digital input alarm delay (18-20)
when i2F=EAL or i2F=bAL
(0 to 255 min) Delay between the detection of the external alarm
condition and its signaling.
When i2F= PAL, it is the interval of time to calculate the
number of pressure switch activation
doA Door open signaling delay (0 to 255 min)
nPS Number of pressure switch activation
(0 to 15) Number of activation, during the did interval, before
signaling an alarm event (i2F=PAL).
If the nPS activation during did time is reached, switch OFF and
ON the instrument to restart normal regulation.
odc Fan/compressor status when door
open
(no; FAn; CPr;F_C;) - no = normal; FAn = fan OFF; CPr =
compressor OFF, F_C = fan and compressor OFF
rrd Outputs restart after doA alarm (n; Y) n = outputs not affected by the doA alarm; Y = outputs
restart with the doA alarm
HES Delta temperature during an Energy
Saving cycle
(-30.0 to 30.0°C; -54 to 54°F)
Sets the increasing value of the setpoint [SET+HES] during the
Energy Saving cycle.
OTHER
Adr Serial address (1 to 247) Identifies the instrument address when connected to a
MODBUS compatible monitoring system.
PbC Type of probe
(ntC, CtC) It allows to set the kind of probe used by the
instrument: ntC = NTC-EU probe, CtC = NTC-US probe. Set
this PbC parameter to CtC to support standard CPC temp
sensors - factory default.
onF ON/OFF key enabling (nU; oFF; ES) nU = disabled; oFF = enabled; ES = not set it
dP1 Thermostat probe display
dP2 Evaporator probe display
dP3 Third probe display (optional)
dP4 Fourth probe display
rSE Real setpoint Shows the setpoint used during the energy saving cycle or
during the continuous cycle.
rEL Software release for internal use
Ptb Parameter table code Read only
Code Parameter Function
Table 7-1 - List of Parameters

Generic Alarm (i2F=EAL) Digital Inputs • 13
8 Digital Inputs
The first digital input 18-20 is enabled with P3P = n.With
P3P = n and i1F = i2F, the second digital input is disabled.
The free voltage digital inputs are programmable by the i1F
and i2F parameters.
8.1. Generic Alarm
(i2F=EAL)
As soon as the digital input is activated the unit will wait
for did time delay before signaling the EAL alarm 
message. The outputs status don’t change. The alarm stops
just after the digital input is de-activated.
8.2. Serious Alarm Mode
(i2F=bAL)
When the digital input is activated, the unit will wait for
did delay before signaling the CA alarm message. The 
relay outputs are switched OFF. The alarm will stop as
soon as the digital input is deactivated.
8.3. Pressure Switch
(i2F=PAL)
If the pressure switch has reached the number of activations
(cycles) of the nPS parameter during the interval time set
by the did parameter, the CA pressure alarm message will
be displayed. The compressor and the regulation are
stopped. When the digital input is ON the compressor is 
always OFF.
If the nPS activation in the did time is reached, switch the
controller OFF and ON to restart normal regulation.
8.4. Door Switch Input (i1F
or i2F=dor)
This input signals the door status and the corresponding 
relay output status through the odc parameter: no = normal
(any change); Fan = Fan OFF; CPr = Compressor OFF;
F_C = Compressor and fan OFF. Since the door is opened,
after the delay time set through parameter doA, the door
alarm is enabled, the display shows the message dA, and
the regulation restarts is rtr=Y. The alarm stops as soon as
the external digital input is disabled again. With the door
open, the high and low temperature alarms are disabled.
8.5. Start Defrost (i1F or
i2F=dEF)
A defrost will start if the right conditions exist. After the
defrost is finished, normal regulation will restart only if the
digital input is disabled; otherwise, the controller will wait
until the MdF safety time is expired.
8.6. Switch the Auxiliary
Relay (i2F=AUS)
When oA2 = AUS, the digital input switches the status of
the auxiliary relay.
8.7. Inversion of the Kind of
Action: Heating -
Cooling (i2F=Htr)
This function allows to invert the regulation of the 
controller: from cooling to heating and vice versa.
8.8. Energy Saving (i2F=ES)
The Energy Saving function allows the setpoint value to be
changed as the result of the [SET+ HES] (parameter) sum.
This function is enabled until the digital input is activated.
8.9. ON - OFF Function
(i2F=onF)
Switches the controller ON and OFF.
8.10.Digital Inputs Polarity
The digital input polarity depends on the i1P and i2P 
parameters.
•i1P or i2P = CL: the input is activated by closing the
contact.
•i1P or i2P = OP: the input is activated by opening
the contact

14 • XR75CX I&O Manual 026-1210 Rev 4
9 RS485 Serial Line
(For Monitoring
Systems)
The RS485 serial line allows the controller to connect to a
monitoring system (MODBUS-RTU compatible) such as
the X-WEB500/3000/300.
10 X-REP Output
(Optional)
Optionally, an X-REP can be connected to the controller
through the dedicated connector.
To connect the X-REP to the controller, the following 
connectors must be used: CAB-51F(1m), CAB-52F (2m),
CAB-55F (5m).
Figure 10-1 - X-REP Output