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AKD Cyclic Position Mode Problem | 24 Jul 2015 | |

AKD Cyclic Position Mode Problem

Hello everyone,

I am usind AKD 3 Amps Driver with appropiate motor for trajectory tracking. Master and AKD communicates via Canopen line. To track desired trajectory, cyclic position mode is selected. Proper PDO mappings are done. 

When sinusoidal trajectory is applied, motor moves as desired. Here is a screenshoot:

However when a constant position command is applied (white line at the bottom of graph), motor startes to turn at constant speed.:

How i can fix this issue.

Thank you.

Comments & Answers

Joerg Muslewski said ...

Joerg Muslewski |


Sorry for the late response.

If you apply a position command which is different from the current position of the motor, the motor will move until the new target position is reached.

Can you provide us more details, which "mode of operations" (6060h) you are using and what the position values are (CAN-objects), when the problem occurs ?


sbarhe said ...

sbarhe |


I am using Cyclic Synchronous Position Mode (Modes of Operation - 0x08)

I am using 2 RPDO and 2 TPDOs. All PDO mappings are set on power-up by master. I would write all the settings which are done via SDOs, but when I clarify the software, I found that RPDOs are asynchronous. I switched these RPDOs to synchronous then problem wiped out.

Thank you.

Daniel Tian | Mon, 01/08/2018 - 09:43

Dear sbarhe,

i met the same issue as you, motor rotate continuously when i set a position command.

how you fix it? i tried to set transimission type of PDO to 01 and 00, doesn't work.

sbarhe | Thu, 01/18/2018 - 13:20

Hi Daniel,

The difference between sinusoidal and constant reference that i sent to driver is PDO sending intervals. When i applied the sinusoidal reference, i was sending a position to driver, each software cycle. But, when i applied to constant reference, i just sent a one message that contains constant reference.

So i figured out that, in cyclic sync mode, driver waits position reference each cycle (interval defines in driver). When interval expires, driver runs in constant speed. That means, trajectory planning must be done in master pc.

So you have to send position reference message each cycle.

Daniel Tian | Thu, 01/18/2018 - 13:43

oh, got it. you explanation is very helpful for me, i will test it later.

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