# S7-400 UDT Addressing **URL:** \ **Category:** Ignition\ **Tags:** siemens\ **Created:** [August 16, 2024, 6:43pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766 "2024-08-16T18:43:35Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Attila\_Lazok](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Attila\_Lazok](https://forum.inductiveautomation.com/u/Attila_Lazok)\ **Post date:** [August 16, 2024, 6:43pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/1 "2024-08-16T18:43:36Z")
Hello all, I am trying to use UDTs from an old S7-400 PLC (No OPC-UA). I have my driver set up and it's communicating, but I am having issues with the addressing. My UDT is in DB11 and it has 10 32 bit boolean clusters. DB11.B000.X00-31, DB11.B001.X00-31, etc. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/4/241ddb4cbc811e94ae0572835c3aac0b14037b0f.jpeg) My understanding is that the addressing would be something like this: 03\_HMI\_B.B000.x00 = DB11.DBX 0.0 = in Ignition = DB11,DBX0.0 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/3/e32638387a13a012dba910483e09af3376fa8593.jpeg) However, it's not working. I am sure I am missing something simple, but I just can't see it. If you have any comments, please share it. Thank you in advance ---
**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:** [August 16, 2024, 6:47pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/2 "2024-08-16T18:47:53Z")
What's not working? Are there any errors in the logs? ---
**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:** [August 16, 2024, 6:49pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/3 "2024-08-16T18:49:03Z")
> [@Attila\_Lazok](#): > > DB11,DBX0.0 Try `DB11,X0.0` ---
**Author:** ![Attila\_Lazok](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Attila\_Lazok](https://forum.inductiveautomation.com/u/Attila_Lazok)\ **Post date:** [August 16, 2024, 6:51pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/4 "2024-08-16T18:51:22Z")
![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/b/bb961fe454fe6833d40b69d103d17aa11a5084e2.png) It comes up with a configuration error ---
**Author:** ![Attila\_Lazok](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Attila\_Lazok](https://forum.inductiveautomation.com/u/Attila_Lazok)\ **Post date:** [August 16, 2024, 7:38pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/5 "2024-08-16T19:38:04Z")
I think I fixed the OPC Item Path, but it still doesn't read or write to the bit. I tried to set the value property, but got an error. (BTW, It tried both X0.0 and DBX0.0) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/e/6e0465cf1ac10e495cc67f8934b9ef43c18f210c.png) ---
**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:** [August 16, 2024, 7:45pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/6 "2024-08-16T19:45:37Z")
Were there any errors in the logs after using the `DB11,X0.0` syntax? Full OPC Item Path to try: `ns=1;s=[lab_S7_400]DB11,DBX0.0` Is your Ignition OPC UA server connection really just named "OPC" instead of its default name? ---
**Author:** ![Attila\_Lazok](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Attila\_Lazok](https://forum.inductiveautomation.com/u/Attila_Lazok)\ **Post date:** [August 16, 2024, 7:49pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/7 "2024-08-16T19:49:41Z")
Yes, it was set up by someone else. (It's a server we use for project testing for various projects) I set up the S7-400 driver and it is communicating. To answer your question, I checked the log and no error showed up... ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/2/f2e15e371b03a1a6e4b95cd82ea9a3df688356e0.png) I copied and pasted your suggested path, but got the same result. ---
**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:** [August 19, 2024, 2:31pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/8 "2024-08-19T14:31:37Z")
Try just `[lab_S7_400]DB11,X0.0` for your "OPC Item Path" ---
**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:** [August 19, 2024, 2:34pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/9 "2024-08-19T14:34:29Z")
Oops, yes, I mistakenly copied his original OPC Item Path when laying out the full one to try. ---
**Author:** ![Attila\_Lazok1](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Attila\_Lazok1](https://forum.inductiveautomation.com/u/Attila_Lazok1)\ **Post date:** [August 19, 2024, 7:21pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/10 "2024-08-19T19:21:54Z")
I did. Still no good. The configuration seems to be OK, yet for the quality I get "Uncertain\_InitialValue" and the Value is not displayed. Also, the error message doesn't contain any details... ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/e/2e2de3f61788cb34202c13f3bcca0d4a575bd1b2.png) ---
**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:** [August 20, 2024, 7:08am UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/11 "2024-08-20T07:08:09Z")
> [@Attila\_Lazok1](#): > > I did. No, you didn't. Why do you keep using `ns=1,s=...`? Just do, what @BRYAN_MOBLEY said: put only `[lab_S7_400]DB11,X0.0` in the OpcItemPath. The syntax `DB11,X0.0` is **CORRECT** one for **Ignition**. > **[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... The `DBX0.0` is **Siemens** syntax in their software (TIA portal, STEP7). Have you checked DB11 in the PLC (online) that it is configured correctly? Is address 0.0 in DB (online) really configured as boolean? Do you REALLY have the latest DB version in the PLC? Did you configure the PLC as described in the Ignition instructions? [Siemens | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.1/ignition-modules/opc-ua/opc-ua-drivers/siemens#considerations-for-1200-and-1500-devices) ![Screenshot_168](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/b/0b22874604392594fb443a624fdd8695b6cdeaab.png) ![Screenshot_169](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/9/19dfc904f8fe95888a74c9a0ba8836ada262b3f1.png) Also, sometimes it happens, if you repeatedly try to configure a tag with wrong data, that '_ **something** _' happens with the Ignition Tag manager (it happened to me a couple of times, especially at the beginning, when I started working with Ignition). In that case, it is best to delete all tags (first export all tags without the ones you have problems with) and restart Gateway. Then import the tags back and try to configure the tag again. Also, show us how did you configured the device connection: ![Screenshot_171](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/6/165f437277bccd78f8dc4fcfdf0f84bf4ec34497.png) (For s7-300, the CPU slot number is ALWAYS 2. For s7-400 is 2 or 3, depends of your power supply (if the power supply is narrow one, then it's 2, if it's wide one, then it is 3)). and how do you have Ignition OPC UA Server configured: ![Screenshot_170](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/2/421ad875dcc87ba432648ce7a9b9efb38392e009.png) ---
**Author:** ![Attila\_Lazok1](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Attila\_Lazok1](https://forum.inductiveautomation.com/u/Attila_Lazok1)\ **Post date:** [August 20, 2024, 12:31pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/12 "2024-08-20T12:31:23Z")
Thank you! That's really useful information. I will check all of those settings. What I find confusing is that my node is connected... ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/b/3bde6a5a51dca45b2d1c2de90d61511c5fe31491.png) ---
**Author:** ![Attila\_Lazok1](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Attila\_Lazok1](https://forum.inductiveautomation.com/u/Attila_Lazok1)\ **Post date:** [August 20, 2024, 12:37pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/13 "2024-08-20T12:37:46Z")
Also, some of the requirements you listed are considerations for 1200 and 1500 devices. I am using S7-400 and Step-7. Not TIA. However, I do wonder if there are some settings I am missing on the Siemens side. If you know Step-7 well, I'd love to hear what you think. As per your "Is the tag really a boolean?" I have screenshots at the beginning of this conversation where you can see how DB11 is set up. ---
**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:** [August 20, 2024, 12:40pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/14 "2024-08-20T12:40:48Z")
I use all 416F-3 PLCs with Step7 v5.6 and 5.7. I don't think I had to change any settings in my Step7 project. I just followed the manual that @zxcslo linked. ---
**Author:** ![Attila\_Lazok1](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Attila\_Lazok1](https://forum.inductiveautomation.com/u/Attila_Lazok1)\ **Post date:** [August 20, 2024, 12:41pm UTC](https://forum.inductiveautomation.com/t/s7-400-udt-addressing/94766/15 "2024-08-20T12:41:51Z")
Thank you! I really appreciate your comment