# Array datatypes **URL:** \ **Category:** General Discussion\ **Created:** [November 11, 2016, 9:09am UTC](https://forum.inductiveautomation.com/t/array-datatypes/12349 "2016-11-11T09:09:24Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [November 11, 2016, 9:09am UTC](https://forum.inductiveautomation.com/t/array-datatypes/12349/1 "2016-11-11T09:09:24Z")
Hi, I’m just starting playing with OPC Tags of type array and I don’t understand a couple of things: I have a S7-300 Siemens PLC and declare a variable like that [attachment=0]declaration1.JPG[/attachment] First off, if I declare an Integer Array I would expect to get an array of integers: what I get instead is an array of bools. Second: I cannot understand how the Data Type declaration, i.e. Integer Array or Long array or Boolean Array plays together with the data type syntax declared in the OPC Item Path address. More precisely I cannot figure out how many bools actually the variable is composed of, when I play with different combinations of those two parameters. Third: are array OPC Items really read only, a part of the workaround to write the complete variable value? Thanks in advance ---
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [November 15, 2016, 7:20pm UTC](https://forum.inductiveautomation.com/t/array-datatypes/12349/2 "2016-11-15T19:20:19Z")
No suggestion out there? ---
**Author:** ![chi](https://avatars.discourse-cdn.com/v4/letter/c/0ea827/32.png) [@chi](https://forum.inductiveautomation.com/u/chi)\ **Post date:** [November 15, 2016, 8:47pm UTC](https://forum.inductiveautomation.com/t/array-datatypes/12349/3 "2016-11-15T20:47:26Z")
I did not try it myself, but as far as i know there is no array support in the Ignition S7 driver. The address DB1,I0 returns a single Integer. Even if you force the client datatype to be an array, the OPC-UA server still returns a single integer. I think the OPC-UA client in Ignition then tries to coerce this integer to an array.