# Question about interpreting BRAKE\_MODE parameter (ID 90) on ACOPOSmicro 80VD100PD.C000-01

**URL:** <https://community.br-automation.com/t/question-about-interpreting-brake-mode-parameter-id-90-on-acoposmicro-80vd100pd-c000-01/7078>\
**Category:** Mechatronics & Motion\
**Tags:** acp10\
**Created:** [May 27, 2025, 12:05am UTC](https://community.br-automation.com/t/question-about-interpreting-brake-mode-parameter-id-90-on-acoposmicro-80vd100pd-c000-01/7078 "2025-05-27T00:05:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![novi](https://avatars.discourse-cdn.com/v4/letter/n/FF8800/32.png) [@novi](https://community.br-automation.com/u/novi)\
**Post date:** [May 27, 2025, 12:05am UTC](https://community.br-automation.com/t/question-about-interpreting-brake-mode-parameter-id-90-on-acoposmicro-80vd100pd-c000-01/7078/1 "2025-05-27T00:05:48Z")

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Hello everyone,

I’m working with an ACOPOSmicro 80VD100PD.C000-01, and I have a question regarding the interpretation of the `BRAKE_MODE` parameter (ID 90).

Since this device only has one digital output for brake control, I decided to use it for motor 1, and for motor 2, I’m controlling the brake via a PLC digital output.

To eliminate the “low brake voltage” error for motor 2, I set the `BRAKE_MODE` parameter to 2, and the error disappeared. However, I’m a bit confused about the interpretation:

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/e/e9fe01979627361ddeb5ec9f2e7f4bab7611416c.png)

- I understand that `BRAKE_MODE` is a 9-bit bitfield, and the value is entered in decimal.
- According to the documentation, decimal 2 corresponds to Bit 1: `CMD_BRAKE at "Controller on" enabled`.
- However, I assumed that to disable brake monitoring (and avoid the error), I should activate Bit 2: `Control monitoring off`, which would be decimal 4.

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/e/e106db5b3ba0d4ae81d269d63f49be8dad398f3d.png)

So my main question is:

Am I interpreting the `BRAKE_MODE` bitmask correctly?  
I f I enter the value 2, am I really activating Bit 1 and not Bit 2?

Any clarification or reference would be greatly appreciated to better understand this configuration.

Thansk in advance.

Regards.

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<div class="post-metadata">

**Author:** ![michael\_w](https://avatars.discourse-cdn.com/v4/letter/m/FF8800/32.png) [@michael\_w](https://community.br-automation.com/u/michael_w)\
**Post date:** [May 28, 2025, 10:27am UTC](https://community.br-automation.com/t/question-about-interpreting-brake-mode-parameter-id-90-on-acoposmicro-80vd100pd-c000-01/7078/2 "2025-05-28T10:27:36Z")

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HI there,

this is just pure numbers in different representation. If you do not feel comfortable interpreting any of those manually, the windows calculator can do this for you:

Step 1: Set it to programmer mode

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/7/7ab2eddaa99684399f78bb3bf8f0479b7f903f6c.jpeg)  
Step 2: Click the icon to switch to binary view  
 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/4/474ee683ae15ff8a90d963b712f72b18f633e64b.png)  
Step 3: Click all the bits you want to set  
 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/9/9aadce13d2b0237b9fb573a84b013a20cfee5dd9.png)

You’ll see that setting only Bit 2 is decimal 4, so 2 is Bit 1, 1 is Bit 0 and so on…

So if you set it to decimal 2, yes, you din’t disable control monitoring.  
Also I am unsure if you can even disable the low voltage monitoring that way.  
To disable a brake, set all the parameters of the brake (MOTOR\_BRAKE\_…) to 0, then the drive should not attempt to open/close it for you