Product Overview
Table Of Contents
© Danfoss | DCS | 2019.04
Data sheet | Superheat controller type EKE 1A, EKE 1B, EKE 1C
DKRCC.PD.RS0.A4.02 | 18
EKE 1C
EKE 1C
EKE 1C
Danfoss
80G336.10
RI 20
CAN H
CAN L
GND
CAN
Jumper
RI 20
CAN H
CAN L
GND
RI 20
CAN H
CAN L
GND
Jumper
Pressure
transmitter
Temperature
sensor
6.2.4 Pressure/ Temperature
signal sharing in EKE 1C
and EKE 1B via CanBus
6.2.5 Using external
signal values via
communication
6.2.6 Signal Sharing Groups
Note:
External pressure
values must be scaled by
X100 time and temperature
values by X10 times before
writing it on EKEs. Example:
8.4 bar gauge is written as
8400, and 2.4 deg
C as 24 via bus
Note:
External signal value
has to be update frequently,
check parameter list for
detail.
In EKE 1C, Signal sharing is possible via CANbus, Signal will be broadcasted once per second to all
controllers by CAN serial line. The following parameters enable/disable broadcasting of local signals:
• [G012 - Signal sharing Pe]
• [G013 - Signal sharing Pc]
• [G014 - Signal sharing S3]
If two or more sensors are connected to same sharing group the controller which start up as the
rst one will broadcast the signal, other controllers will ignore broadcasted signal. If the receiving
controllers has not received a shared signal from another controller for 3 seconds (parameter G003
CAN bus min update interval) it will start broadcast the local sensor.
When more controllers are connected via CANbus each end of the bus must be terminated with
a jumper between CANH and R120.
Note:
Broadcasting is not possible
via Modbus. In case of Sensor
error, broadcast will stop.
Note:
Please make sure that each
controller has a dierent
controller address (G001) before
sharing them via CANbus. Only
after setting dierent address
should controllers be connected
together for sharing.
Only Pe, Pc and S3 parameters
can be shared using CANbus.
EKE 1B/1C controllers can receive the external sensor values like Po, Pc, S2, S3 and S4 via bus
communication. In some applications, the suction pressure and/or the refrigerant temperature on
the evaporator outlet, is measured by a system controller. This is often the case if the suction
pressure is used to trigger low temperature/pressure alarms by the systems main controller.
In these cases the sensors can be omitted from EKE , and the sensor values can be received via
modbus instead. This requires that the systems main controller continuously transmits these values
to EKE, If no new sensor value is received within dened MODbus time interval in seconds i.e G004
of the last transmission, the EKE will raise sensor alarm which will stop the regulation.
Example: The suction gas temperature S2 and the evaporator pressure Pe can be set by activating
bus shared sensor conguration registers i.e “I040 = 5” and “I044 = 8” respectively.
Master controller
Danfoss
80G337.10
RS485 MODbus
Sensor values
EKE controller
Pressure transmitter
Temperature sensor
6.3 Sensor Correction
The input signal from all connected sensors can be corrected. A correction will only be necessary if
the sensor cable is long and has a small cross-sectional area. All displays and functions will reect
the corrected value.
Regarding temperature sensor, PT1000 temperature sensor is sensitive with longer cable length and
type. It is must to perform a sensor correction if the resistance of the temperature sensor deviates.
Normally,1 degree C corresponds to approximately 4 ohms.
Address 0 is invalid, and must not be used.
Address 126 and 127 is reserved for remote displays
A controller knows its own address and knows from which address the broadcast is coming, this
information is used to discard broadcast signals for controllers outside own group.
Shared signals is divided into groups by use of the address number
Group 1 address 1 to 31
Group 2 address 32 to 63
Group 3 address 64 to 95
Group 4 address 96 to 125