# Siemens S7-300 addressing for M bits

**URL:** <https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [May 14, 2025, 2:10pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258 "2025-05-14T14:10:07Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Matrix\_Engineering](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/matrix_engineering/32/19781_2.png) [@Matrix\_Engineering](https://forum.inductiveautomation.com/u/Matrix_Engineering)\
**Post date:** [May 14, 2025, 2:10pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258/1 "2025-05-14T14:10:07Z")

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I am trying to get data from an S7-300 (CPU 314). I am using a Helmholz NET adapter. Using the Siemens S7-300 driver it shows connected.

To start with I want to read some M address bits. I have checked the manual but there are no examples for that. I tried [device]M2.0 etc but the tag comes up with configuration error. Any tips?

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**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\
**Post date:** [May 14, 2025, 2:29pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258/2 "2025-05-14T14:29:33Z")

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Try MX2.0...

> **[Siemens | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.1/ignition-modules/opc-ua/opc-ua-drivers/siemens#address-syntax)**
>
> The Siemens drivers in Ignition support basic connections to S7 devices. Ignition connects to these PLCs via TCP/IP using the S7 protocol. Similar to Modbus and some Allen Bradley connections, the Siemens S7 devices do not support tag browsing. You...

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<div class="post-metadata">

**Author:** ![Matrix\_Engineering](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/matrix_engineering/32/19781_2.png) [@Matrix\_Engineering](https://forum.inductiveautomation.com/u/Matrix_Engineering)\
**Post date:** [May 14, 2025, 3:06pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258/3 "2025-05-14T15:06:07Z")

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Thanks!

Next is DB1.DBD16, I tried DB1,DBD16 and DBD16,DB1... the type is DINT in the DB

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [May 14, 2025, 3:29pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258/4 "2025-05-14T15:29:05Z")

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`DB1,D16` or `DB1,DI16`?

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<div class="post-metadata">

**Author:** ![Matrix\_Engineering](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/matrix_engineering/32/19781_2.png) [@Matrix\_Engineering](https://forum.inductiveautomation.com/u/Matrix_Engineering)\
**Post date:** [May 14, 2025, 3:52pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-addressing-for-m-bits/106258/5 "2025-05-14T15:52:33Z")

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> [@Kevin.Herron](#):
>
> DB1,D16

Thanks =)