CPB Modbus RTU Technical Manual

Technical Manual CPB

Fieldbus: Modbus RTU

Valid for firmware version FIR-v2213 and higher Technical Manual version: 1.1.1


The products of the CPB series are motor controllers in plug‑in module format for integration in your own development. The CPB3-... and CPB6-... variants can control both BLDC motors and stepper motors; the CPB15 variant is suitable for BLDC motors only.

This manual describes the integration of the CPB in your motherboard and the functions of the controller. It also shows how you can address and program the controller via the communication interface.

You can find further information on the product on us.nanotec.com.

Version information


Manual version Date Changes Firmware version Hardware version
1.0.0 01/2022 First edition FIR-v2139 W003
1.1.0 07/2022 FIR-v2213 W003
1.1.1 09/2022 Correction of the routing example in the chapter Digital inputs. FIR-v2213 W003


Manual version Date Changes Firmware version Hardware version
1.0.0 01/2022 First edition FIR-v2139 W004
1.1.0 07/2022 FIR-v2213 W004
1.1.1 09/2022 Correction of the routing example in the chapter Digital inputs. FIR-v2213 W004


Manual version Date Changes Firmware version Hardware version
1.0.0 01/2022 First edition FIR-v2139 W005
1.1.0 07/2022 FIR-v2213 W005
1.1.1 09/2022 Correction of the routing example in the chapter Digital inputs. FIR-v2213 W005

Copyright, marking and contact

© 2013 – 2022 Nanotec Electronic GmbH & Co. KG. All rights reserved.

Nanotec Electronic GmbH & Co. KG

Kapellenstraße 6

85622 Feldkirchen


Phone: +49 89 900 686-0

Fax: +49 (89) 900 686-50




Intended use

The CPB serves to control stepper motors or BLDC motors and is used as a component in drive systems in a wide range of industrial applications.

The controller must be connected to motors via a suitable motherboard. The system boundary of the CPB ends at the connectors.

Use the product as intended within the limits defined in the technical data (in particular, see Electrical properties and technical data) and the approved Environmental conditions.

Under no circumstances may this Nanotec product be integrated as a safety component in a product or system. All products containing a component manufactured by Nanotec must, upon delivery to the end user, be provided with corresponding warning notices including instructions for safe use and safe operation. All warning notices provided by Nanotec must be passed on directly to the end user.

Target group and qualification

The product and this documentation are directed towards technically trained specialists staff such as:

  • Development engineers
  • Plant engineers
  • Installers/service personnel
  • Application engineers

Only specialists may install, program and commission the product. Specialist staff are persons who

  • have appropriate training and experience in working with motors and their control,
  • are familiar with and understand the content of this technical manual,
  • know the applicable regulations.

Warranty and disclaimer

Nanotec is not liable for damage and malfunction from installation errors, failure to observe this document, or improper repair. Responsible for the selection, operation, use of our products is the plant engineer, oper­ator and user. Nanotec accepts no liability for product integration in the end system. The general terms and conditions at www.nanotec.com apply (customers of Nanotec Electronic USA please see us.nanotec.com). Note: Product modification / alteration is illicit.

EU directives for product safety

The following EU directives were observed:

  • RoHS directive (2011/65/EU, 2015/863/EU)

Other applicable regulations

In addition to this technical manual, the following regulations are to be observed:

  • Accident-prevention regulations
  • Local regulations on occupational safety

Used icons

All notices are in the same format. The degree of the hazard is divided into the following classes.

  • The CAUTION notice indicates a possibly dangerous situation.
  • Failure to observe the notice may result in moderately severe injuries.
  • ► Describes how you can avoid the dangerous situation.
  • Indicates a possible incorrect operation of the product.
  • Failure to observe the notice may result in damage to this or other products.
  • ► Describes how you can avoid the incorrect operation.
Tip: Shows a tip for the application or task.

Emphasis in the text

The following conventions are used in the document:

Underlined text indicates cross references and hyperlinks:

Text set in italics marks named objects:

  • Read the installation manual.
  • Use the Plug & Drive Studio software to perform the auto setup.
  • For software: You can find the corresponding information in the Operation tab.
  • For hardware: Use the ON/OFF switch to switch the device on.

A text set in Courier marks a code section or programming command:

  • The line with the od_write(0x6040, 0x00, 5 ); command has no effect.
  • The NMT message is structured as follows: 000 | 81 2A

A text in "quotation marks" marks user input:

  • Start the NanoJ program by writing object 2300h, bit 0 = "1".
  • If a holding torque is already needed in this state, the value "1" must be written in 3212h:01h.

Numerical values

Numerical values are generally specified in decimal notation. The use of hexadecimal notation is indicated by a subscript h at the end of the number.

The objects in the object dictionary are written with index and subindex as follows: <Index>:<Subindex>

Both the index as well as the subindex are specified in hexadecimal notation. If no subindex is listed, the subindex is 00h.

Example: Subindex 5 of object 1003h is addressed with 1003h:05h, subindex 00 of object 6040h with 6040h.


The numbering of individual bits in an object always begins with the LSB (bit number 0). See the following figure, which uses data type UNSIGNED8 as an example.

Counting direction (arrows)

In figures, the counting direction is always in the direction of an arrow. Objects 60C5h and 60C6h depicted as examples in the following figure are both specified as positive.