# X20DS838A size of input/output data

**URL:** <https://community.br-automation.com/t/x20ds838a-size-of-input-output-data/6068>\
**Category:** Controls & Vision\
**Tags:** x20, io\
**Created:** [February 27, 2025, 7:44pm UTC](https://community.br-automation.com/t/x20ds838a-size-of-input-output-data/6068 "2025-02-27T19:44:36Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bengtssond](https://avatars.discourse-cdn.com/v4/letter/b/FF8800/32.png) [@bengtssond](https://community.br-automation.com/u/bengtssond)\
**Post date:** [February 27, 2025, 7:44pm UTC](https://community.br-automation.com/t/x20ds838a-size-of-input-output-data/6068/1 "2025-02-27T19:44:36Z")

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Hi,

With the new X20DS838A module that supports 32 bytes input and output for every channel, I saw that the size of input/output was configured in steps of 4 bytes

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/7/73a3dc86d5cf9c4d7d17f22b9220d8ba21ff8198.png)

Compared to X20DS438A that are in steps of 1 byte.

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/a/a25c4f73931c71311ff5e7bd1e2f0d868aecfd50.png)

I have IO-Link devices that for example are using 7 bytes output and 18 bytes input. How will that work with the new module? Are the device I want to communicate with skipping the addtional bytes that are configured in AS?

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**Author:** ![stephan.herbig](https://avatars.discourse-cdn.com/v4/letter/s/FF8800/32.png) [@stephan.herbig](https://community.br-automation.com/u/stephan.herbig)\
**Post date:** [March 4, 2025, 9:37am UTC](https://community.br-automation.com/t/x20ds838a-size-of-input-output-data/6068/2 "2025-03-04T09:37:58Z")

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Hallo Daniel,

you can use various data types to exchange exactly 9 bytes of data, or you can use an octet array with 12 bytes of data. In this case, the 3 bytes that are too many will not contain any values.

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/d/de1663188e803b8fa6e4565d201cc723b829e3c6.jpeg)

Gruss  
Stephan

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<div class="post-metadata">

**Author:** ![bengtssond](https://avatars.discourse-cdn.com/v4/letter/b/FF8800/32.png) [@bengtssond](https://community.br-automation.com/u/bengtssond)\
**Post date:** [March 11, 2025, 7:57am UTC](https://community.br-automation.com/t/x20ds838a-size-of-input-output-data/6068/3 "2025-03-11T07:57:08Z")

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Hallo Stephan,

Ok, thanks for the info!