CRD FLEX (CRK series) driver: communicating through Modbus

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CRD FLEX (CRK series) driver: communicating through Modbus

Postby om_tech_support_SZ » Tue May 30, 2017 1:35 pm

CRD FLEX (CRK series) driver: communicating through Modbus

Q: I am currently using the CRD Flex type driver to drive a motor used in a camera focusing application. I would like to communicate to the driver using Modbus RTU through RS-485 communication as this motor is one of the motors in a 3-axis system. However, I was not able to start the motor when I sent a start input to the driver.

A: Thank you for your inquiry regarding the CRD Flex type driver (CRK series driver). For the CRD Flex driver, follow the guidelines for “Method of control via Modbus RTU” which can be found starting on page 97 of the manual below.

CRK FLEX manual: ... 112-7E.pdf
With the CRD Flex type driver, please make sure that all the drivers are connected through CN6 and CN7 with the appropriate pin assignment for the communication cable which is shown on page 39 of the manual:

pin assignments.png
pin assignments.png (113.25 KiB) Viewed 45867 times

After checking the connection, please also make sure the switches on the driver match with the communication setting in the software that you are using for Modbus RTU communication. These settings include the slave address, Baud rate, and Termination resistor and are shown on pages 101 and 102 of the manual. A screenshot from the manual with some of the setting parameters is shown below:

setting the switches.PNG
setting the switches.PNG (258.64 KiB) Viewed 45867 times

Once the switches have been set, there are some parameters that will need to be changed in order for you to communicate through Modbus RS-485 communication. These settings will need to be changed by either using the OPX-2A control module or by connecting the driver to a PC and using our MEXE02 software. In order to connect the CRD driver to the PC, then you will also need the communication cable that we offer – CC05IF-USB. The following is a list of the parameters that can be changed for operation through Modbus RS-485 communication:

modbus setting.PNG
modbus setting.PNG (125.98 KiB) Viewed 45867 times

For your application, you must change the START input mode under the I/O Application to “RS-485 communication.” The default setting for the “Start Input Mode” for the CRD driver is I/O. By changing it to “RS-485 Communication”, you will now be able to provide the start signal to the driver through Modbus communication. You can follow a similar procedure for the rest of the parameter list. Please reference the MEXE02 software screenshot below for the location of the parameters.

mexe02 settings.PNG
mexe02 settings.PNG (163.98 KiB) Viewed 45867 times

Finally, after the parameters have been changed, you will need to write to the driver. After writing has been completed, then the power will need to be cycled for the new system parameters to come into effect. Once the power is restored, you can now start operation through Modbus communication.

As an addition FYI, the FLEX products allow you to pre-program the operation data via the MEXE02 software, store it inside the driver, and use Modbus RTU to trigger the operation data that has been stored in the driver. This could result in a much quicker setup and will allow you to start operating through Modbus communication sooner.

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