CIM/CIU fieldbus - control of pumps and pump systems



The Grundfos fieldbus concept is the ideal solution for complete control and monitoring of pumps and pump systems. The innovative Communication Interface Module (CIM) and the Communication Interface Unit (CIU) enable data communication via open and interoperable networks.

The Grundfos CIM/CIU communication interfaces offer ease of installation and commissioning, user-friendliness, and great value for money in the long term. All modules are based on standard functional profiles for easy integration into the network and easy understanding of data points.

CIM modules are add-on modules that allow communication with E-pumps, circulator pumps, Multi Pump Controller (CU 352), Hydro Multi-E, Hydro Multi-B and Dedicated Controls (CU 362) and Level Control LC 2x1 for wastewater pumps.

The CIU communication interface unit is for products with a GENIbus interface such as Motor protection MP 204, external variable speed drives (CUE), Wastewater-AutoAdapt pumps or large DDA XL dosing pumps. CIU units have an integrated 24 to 240 V power supply and are prepared for wall-mounting or DIN-rail mounting.
For small DDA dosing pumps use  E-box 150 / E-box 200 or E-box 500 units.

The CIM/CIU interfaces support the following fieldbus standards:

  • Modbus RTU
  • Modbus TCP
  • BACnet MS/TP
  • BACnet IP
  • LONworks
  • 3G/4G cellular data connection (Modbus TCP / SMS)
  • 3G/4G cellular Grundfos Remote Management/ Grundfos iSolution Cloud


  • CIM/CIU 100/110 LON is mainly used for HVAC applications in buildings
  • CIM/CIU 150 Profibus DP is mainly used for factory and process automation
  • CIM/CIU 200 Modbus RTU is used for versatile automation e.g. HVAC and wastewater applications
  • CIM/CIU 250/25x GSM/GPRS is mainly used for water supply and wastewater applications
  • CIM/CIU 260/26x 3G/4G cellular data connection is mainly used for water supply and wastewater applications
  • CIM/CIU 270/27x GRM/GPRS  is used together with Grundfos Remote Management
  • CIM/CIU 280/28x 3G/4G cellular is used together with Grundfos Remote Management/ Grundfos iSolution cloud
  • CIM/CIU 300 BACnet is used for building automation
  • CIM/CIU 500 Ethernet can be used for Modbus TCP, PROFINET IO, BACnet IP and GRM IP

Features and benefits

  • Based on standard functional profiles
  • One solution for all products with a modular design prepared for future needs
  • One solution offering complete process monitoring and control
  • Easy to install and commission, as Grundfos delivers the required support files and functional profile manuals
  • Flexible wide range power supply 24-240 VAC/VDC (CIU unit)
  • Pumps and controllers have better reliability with reduced downtime, due to monitoring and control functionality on a PLC/BMS/SCADA system
  • The operational cost of pumps can be lowered by reducing setpoints to match precise system needs via remote control
  • Remote monitoring and control via PLC/BMS/SCADA systems reduce manual settings, monitoring time and travel time to sites or installations
  • Enable predictive maintenance and fast reaction time on process changes and exceptions

Selection table

The selection table in the CIM CIU communication interface brochure makes
it easy to select the needed CIM or CIU communication interface (look at tab brochures)    


  • Easy to install and commission
  • Flexible power supply
  • Based on standard functional profiles





For complete control of pump systems, the Grundfos fieldbus concept is the right solution. The innovative Communication Interface Module (CIM) and the Communication Interface Unit (CIU) enable data communication via open and interoperable networks

Grundfosliterature-6162918.pdf (2 MB)



Information and advice

Grundfos is a world-wide provider of pumps and related systems. We have a trained staff of service engineers who will be able to support you during the installation phase of the pump or solution. Grundfos products are manufactured to very high standards, which helps to ensure a long life. Our many years of experience of different kinds of installation and with installation techniques are also key factors for maximising the lives of your Grundfos products or systems.

We will be able to support you with the following:

  • Information about the proper protection of our pumps
  • Advice on the physical positioning of the pump for necessary service/repair
  • Advice on the physical positioning of the pump to maintain proper operation
  • Correct cabling to fulfil the requirements of good practice and electromagnetic compatibility.

Please contact your local Grundfos company to obtain full support for your new installation.



Service agreement

A Grundfos service agreement ensures the efficient and uninterrupted operation of your pump system and gives you access to Grundfos service centres and authorised service partners worldwide, 24 hours a day.

Prevention is better, and more cost-effective, than cure

Once you have purchased your pump, you will want it to function efficiently and reliably; a formal service agreement with Grundfos will give you peace of mind. It also makes sound economic sense, giving you a firm costing for your maintenance budget and access to substantial discounts.

You simply combine a range of service programmes to suit your needs – and then let us carry out scheduled maintenance visits to prevent downtime. We offer three types of service agreement, available for all pumps:

  • Basic
  • Extended
  • Total.


Whichever agreement you choose, your equipment will always be serviced by specially trained staff.

The cost-effective choice

Well-maintained pumps can reduce your energy consumption by up to 50 %. Furthermore, it's worth remembering that in a series of pumps working together, one faulty pump can affect all the others. A Grundfos service agreement keeps the total cost of operating a pump to a minimum. Our careful calculation of the life-cycle cost of all our products means that we have an overview of the true costs of owning each of our pumps.

Signing up for a service agreement and letting our highly-skilled service technicians service your pumps is a safeguard against unforeseen expenditure. Regular servicing and maintenance of your pumps will ensure that they operate with optimum efficiency.




The purpose of CAPS is to provide a complete tool that contains both an extensive catalogue of Grundfos products and a sizing program to select the most suitable pump for your application.

There is also a comprehensive pump replacement selection function for central heating circulator pumps, hot water pumps and wastewater S pumps, and a function for producing professional quotations that include curves, drawings, quotation texts, wiring diagrams, etc.

Last but not least, the software contains the instruction and operating manuals for nearly all Grundfos pumps in multiple languages. Service drawings, exploded views and parts lists are available for all sewage products as well as several other pump types.

CAPS is available in two versions: WinCAPS, available on CD-ROM, and the online version WebCAPS, available at the Grundfos website. Additional features available in WebCAPS include CAD Drawings and Literature.

Spare parts

Spare parts

Sales office

Contact us

Select country to contact your local sales company


+2710 248 6000


16 Lascelles Road, Meadowbrook, Germiston

Service center

Contact us

Select country to contact your local service center


+2710 248 6000, 24hr emergency number: +27 83 642 0926


16 Lascelles Road, Meadowbrook, Germiston