Modbus Installation - Danfoss EKE Installation Manual

Modbus installation

• For the Modbus cable, it is best to use 24 AWG shielded twisted-pair cable with a shunt capacitance
of 16 pF/ft and 100Ω impedance.
• The controller provides an insulated RS485 communication interface which is connected to the
RS485 terminals (see connection overview).
• The max. permissible number of devices simultaneously connected to RS485 cable output is 32.
• The RS485 cable is of impedance 120 Ω with maximum length of 1000 m.
• Terminal resistors 120 Ω for terminal devices are recommended at both ends.
• The EKE communication frequency (baud rate) can be one of the following: 9600, 19200 or 38400
baud, default 19200 8E1.
• The default unit address is 1.
• For detailed info on Modbus PNU, check EKE 100 manuals
Manual resetting Modbus address:
1. Remove Supply power from EKE 100
2. Connect terminal BAT+ to +5V
3. Connect EKE 100 to power
4. Now Modbus communication options are reset to factory default(Address 1, 19200 baud, mode 8E1)
Signal Sharing
Power and backup supply sharing
• 1 EKE 100 and 1 EKE 2U can share power supply(AC or DC)
• 2 EKE 100 and 1 EKE 2U can share power supply only with DC
Pressure sensor sharing
• Physical sharing is allowed if used within the same controller and not allowed if 2 or more
controllers are used for sharing.
• Modbus sharing is allowed with more than 1 controller.
• Software sharing is allowed within one controller by selecting option Common.
Temperature sensor sharing
• Physical sharing is not allowed.
• Modbus sharing is allowed with more than 1 controller.
• Software sharing is allowed within one controller by selecting option Common.
© Danfoss | Climate solutions | 2023.07
Danfoss
93Z9023
A+
B-
Not in use
GND
AN433741508202en-000203 | 7