# OPC Tag (Float Array) not supporting PLC Tag (Real\[10\]) **URL:** \ **Category:** Ignition\ **Tags:** perspective\ **Created:** [October 16, 2025, 12:48am UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496 "2025-10-16T00:48:38Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 12:48am UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/1 "2025-10-16T00:48:38Z")
Hi All, The tag I have created for a PLC tag that is REAL[10] is not working, it only works when I use ns=1;s=[TOPIC]ARRAY\_NAME[i] as the item path. If I use ns=1;s=[TOPIC]ARRAY\_NAME (without indexing an array element), I will get this Quality error: > “Error\_Configuration("Bad\_AttributeIdInvalid: The attribute is not supported for the specified Node.")” It looks like Ignition is not recognizing the array as an OPC node, because the item path seems fine. Screenshots: #### Float Array Tag in Ignition (DOESN’T WORK): ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/6/b6295d6aea5e77d6731dd7c389c1f9cf241b6063.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/2/12970b6368a8645286d3e2120799c0d1cc319e98.png) Item Path copied from OPC Browser: ns=1;s=[FMS\_PLC\_03\_00A]B100\_MTCW\_CT\_STOPsp Error: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/7/470f021936c9086341b7bde3a68936559e0bbb8e.png) #### Float Array Tag in Ignition but indexing an element (WORKS): ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/2/f2bf01943d85eaf7e27114c7271c8728f670bfca.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/0/701f3793b8b85d17d7b064e321219ef36b1bb799.png) Item Path used: ns=1;s=[FMS\_PLC\_03\_00A]B100\_MTCW\_CT\_STOPsp[0] I might be missing something. Thank you in advanced for your help! Danny ---
**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:** [October 16, 2025, 12:50am UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/2 "2025-10-16T00:50:00Z")
Many of the older Ignition drivers expose arrays as a folder containing a tag per element. You can’t address the array itself in these drivers. ---
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 4:14am UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/3 "2025-10-16T04:14:29Z")
Hi Kevin, thank you for the explanation. Can this be fixed by updating Ignition, the drivers, both, or there is no solution for this? ---
**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:** [October 16, 2025, 10:37am UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/4 "2025-10-16T10:37:42Z")
No, it’s just not a functionality those drivers have. What’s your use case? Array support in Ignition tags is weak and there is no performance gain at the driver level either way - it reads the array not individual tags at that level. ---
**Author:** ![liam1](https://avatars.discourse-cdn.com/v4/letter/l/e68b1a/32.png) [@liam1](https://forum.inductiveautomation.com/u/liam1)\ **Post date:** [October 16, 2025, 2:32pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/5 "2025-10-16T14:32:02Z")
A solution I have implemented is a polled opc read, which converts the data into a Ignition Float Array tag. When I want to write back, I have a Float Array tag with a change script. Here is the function I use, works pretty well, you just need to remember to set the correct size. ```python def getArrayValues(opcPath,size): return [i.value for i in system.opc.readValues('Ignition OPC UA Server', ['{}[{}]'.format(opcPath,i) for i in range(0,size)])] def setArrayValues(opcPath,values,size): itemPaths= ['{}[{}]'.format(opcPath,i) for i in range(0,size)] system.opc.writeValues('Ignition OPC UA Server', itemPaths, [round(x,2) for x in values]) ``` Hope this helps ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/7/3713b0acd7fd3183c4437d1575a0f858a62d498b.png) ---
**Author:** ![robertm](https://avatars.discourse-cdn.com/v4/letter/r/ea5d25/32.png) [@robertm](https://forum.inductiveautomation.com/u/robertm)\ **Post date:** [October 16, 2025, 3:01pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/6 "2025-10-16T15:01:06Z")
What’s the use case for using float array tags? I use array folders within UDTs or of UDTs and it seems to make management, indirects and organization so much easier. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [October 16, 2025, 3:30pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/7 "2025-10-16T15:30:50Z")
If you have a very specific need for this, it is implemented in my alternate driver. But note that writes to individual array members are not supported. ---
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 9:08pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/8 "2025-10-16T21:08:04Z")
Thank you!! ---
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 9:09pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/9 "2025-10-16T21:09:24Z")
I don’t have a specific need at the moment, just curious to know if I was doing something wrong on my end. I will keep that in mind. Thank You, Phil! ---
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 9:11pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/10 "2025-10-16T21:11:10Z")
I was trying to grab an array all at once with one opc tag, to minimize the number of tags created in ignition. It is not like it was too long to create individual tags, I experimenting with that datatype just to know how it worked. ---
**Author:** ![danny.lazaro](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/danny.lazaro/32/79188_2.png) [@danny.lazaro](https://forum.inductiveautomation.com/u/danny.lazaro)\ **Post date:** [October 16, 2025, 9:13pm UTC](https://forum.inductiveautomation.com/t/opc-tag-float-array-not-supporting-plc-tag-real-10/111496/11 "2025-10-16T21:13:03Z")
Sounds good, my use case doesn’t require it. I can work with it, I was just experimenting with that datatype and I was curious if I was doing something wrong on my end. Thanks Kevin!