# Issue in reading modbus data using 750-653

**URL:** <https://www.wago.community/t/issue-in-reading-modbus-data-using-750-653/2608>\
**Category:** CODESYS\
**Tags:** codesys\
**Created:** [March 3, 2026, 7:07am UTC](https://www.wago.community/t/issue-in-reading-modbus-data-using-750-653/2608 "2026-03-03T07:07:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![cran](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@cran](https://www.wago.community/u/cran)\
**Post date:** [March 3, 2026, 7:07am UTC](https://www.wago.community/t/issue-in-reading-modbus-data-using-750-653/2608/1 "2026-03-03T07:07:52Z")

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Hello everyone,

I am using a **WAGO 750-881** and **750-653** I/O card setup, i am reading data of rs485 on 750-653 first i get xml file from wago io check then added in codesys 2.3 in kbus after that in modbus master when i added the serial interface which shows the com port 2 and I am getting the following errors:

- `MBCFG_SERCOM_ERROR : 9`

- `MBCFG_ERROR : MBCFG_START_UP`

MBCFG\_SERCOM\_ERROR 9 means “"these transfer parameters are not supported by COM port”

Can anyone guide me on how to **resolve this issue**? I would really appreciate any suggestions or troubleshooting tips.

Here is the setting which i have done for reading the data of modbus slave

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/5/51b493b4952ef6ec4f53bfb43d89b3ceec90daf6.png)

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**Author:** ![WagoIcard](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/wagoicard/32/1508_2.png) [@WagoIcard](https://www.wago.community/u/WagoIcard)\
**Post date:** [March 16, 2026, 11:49pm UTC](https://www.wago.community/t/issue-in-reading-modbus-data-using-750-653/2608/2 "2026-03-16T23:49:47Z")

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Hello, First, do you have a 750-653 or a 750-653/003-000 ?  
If you don’t have a 750-653/003-000, the modules is locked on it’s default setting and can’t be changed.