TIC T834 Current Limit Problem


I have just received my TIC T834, had its headers and terminal blocks mounted. Also installed the TIC Control Center software.

My initial tests with default settings are OK.

However, whenever I try to increase the current limit beyond 192mA, the software de-energizes the motor and displays an error message “safe start violation”. And only way to recover is to returning back to the default settings.

T834 connects to the PC via USB. Vin is provided by a power supply set to 2.8v & 3.2A limit.

Does anyone have a suggestion to get over this problem?

Thanks in advance,

Hello, Phar.

Can you check the “Status” tab when the error occurs to see if the “Count” of any other errors has increased? In particular, I suspect the Low VIN error might be triggering as described in the “Testing the motor for the first time” heading of the “Configuring and testing the stepper motor” section of the Tic user’s guide.

To clarify, when this error occurs, what happens when you try to click the “Resume” button? If you continue to get an error, can you also check to see if any other errors are triggering when you try to resume?


Hi BrandonM,

Thank you so much for this prompt reply. Below is the screenshot right after relaunching the Control Software after the fault occurs:

Low VIN does not seem to be triggered. It’s just “Command Timeout” and “Safe Start Violation”.

And when I try to Resume, as you suggested, I hear a bried 1-step tick sound on the motor, and the status bar says “Motor de-energized because of motor driver error” but this message shows just instantly and then switches back to the message “motor de-energized because of safe-start violation”:

And as a result of this, Motor Driver Error count increases:

And when I’m done with the Resume button, the final look of the Errors panel is like this:

As mentioned in the “Testing the motor for the first time” heading of the “Configuring and testing the stepper motor” section of the user’s guide, the Tic T834 might report a “Motor driver error” without reporting a “Low VIN” error because of the DRV8834’s under-voltage lockout fault. Can you tell me more about your power supply and stepper motor? Do you have a higher voltage supply you could try (e.g. something in the 6-9V range)?


I can try that but my motor’s rated voltage is 2.8V. Would you recommend going beyond that?

The motor is: https://www.pololu.com/product/2690

Thank you,

A quick update for possible future followers of this topic:

I took the risk to go beyond the rated value of 2.8V. The setup was able to achieve 1800 full step pulses/sec with a VIN=12V, mixed 50% decay, 1600pulse/sec2 acceleration.

Please note that I do not know whether this is a recommended mode of operation.


I am glad you were able to get it working. Yes, as long as you are using a current limiting driver and have the current limit set equal to or lower than the current per phase rating of your motor, it is safe to run it at a higher voltage. In fact, there can even be a benefit in doing so; more information can be found in the FAQ listed under the “FAQs” tab of the Tic T834 product page.


1 Like