# How should I read S7-300 DB addresses (e.g. DB916,DBD228) in Ignition OPC?

**URL:** <https://forum.inductiveautomation.com/t/how-should-i-read-s7-300-db-addresses-e-g-db916-dbd228-in-ignition-opc/116269>\
**Category:** Ignition\
**Tags:** opcua, ignition83, siemens\
**Created:** [July 3, 2026, 10:42pm UTC](https://forum.inductiveautomation.com/t/how-should-i-read-s7-300-db-addresses-e-g-db916-dbd228-in-ignition-opc/116269 "2026-07-03T22:42:20Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![galeman](https://avatars.discourse-cdn.com/v4/letter/g/eb9ed0/32.png) [@galeman](https://forum.inductiveautomation.com/u/galeman)\
**Post date:** [July 3, 2026, 10:42pm UTC](https://forum.inductiveautomation.com/t/how-should-i-read-s7-300-db-addresses-e-g-db916-dbd228-in-ignition-opc/116269/1 "2026-07-03T22:42:20Z")

</div>

I'm configuring an **OPC Tag** in Ignition to read a value from a **Siemens S7-300** PLC.

The PLC address I was given is:

```python
DB916,DBD228

```

The OPC device name in Ignition is:

```python
L12_VarioAsep

```

The OPC Item Path is currently configured as:

```python
ns=1;s=[L12_VarioAsep]DB916,REAL228

```

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/e/ae8e3477ee05577aa0c3f2d2b33fd1dabd05c0c9.png)

The tag quality is **Good** (no errors or Bad quality), so the communication appears to be working. However, the tag value is **always 0** , even though I expect it to contain a non-zero value.

My questions are:

- Is this the correct OPC Item Path for the PLC address `DB916,DBD228`?
- Should `DBD228` be read as `REAL228`, `DINT228`, or another data type?

Unfortunately, I don't have access to the PLC project or STEP 7/TIA Portal.

Any suggestions or troubleshooting steps would be greatly appreciated. Thank you!

---

<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:** [July 3, 2026, 11:15pm UTC](https://forum.inductiveautomation.com/t/how-should-i-read-s7-300-db-addresses-e-g-db916-dbd228-in-ignition-opc/116269/2 "2026-07-03T23:15:49Z")

</div>

> [@galeman](#):
>
> `DB916,DBD228`

The D is probably DWord, so I'd expect it to look like `[Device]DB916,D228` in Ignition

---

<div class="post-metadata">

**Author:** ![BRYAN\_MOBLEY](https://avatars.discourse-cdn.com/v4/letter/b/db5fbb/32.png) [@BRYAN\_MOBLEY](https://forum.inductiveautomation.com/u/BRYAN_MOBLEY)\
**Post date:** [July 6, 2026, 5:37pm UTC](https://forum.inductiveautomation.com/t/how-should-i-read-s7-300-db-addresses-e-g-db916-dbd228-in-ignition-opc/116269/3 "2026-07-06T17:37:19Z")

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If you just use [L12\_VarioAsep]DB916,REAL228 for the path and Float for the data type, do you get values?