# ControlLogix String type

**URL:** <https://forum.inductiveautomation.com/t/controllogix-string-type/783>\
**Category:** Archived Topics\
**Created:** [August 20, 2008, 2:51pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783 "2008-08-20T14:51:35Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![JoshMan](https://avatars.discourse-cdn.com/v4/letter/j/a4c791/32.png) [@JoshMan](https://forum.inductiveautomation.com/u/JoshMan)\
**Post date:** [August 20, 2008, 2:51pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783/1 "2008-08-20T14:51:35Z")

</div>

Hey,

I’m trying trying to receive a string from a ControlLogix PLC. The string will contain an ID code and a material description. When I browse it in the SQL OPC browser all I am getting is folders with the array. Am I doing something wrong? How do I get it to come in as a string and record as a string?

ANy help is greatly appreciated.

---

<div class="post-metadata">

**Author:** ![Robert.McKenzie](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/robert.mckenzie/32/4134_2.png) [@Robert.McKenzie](https://forum.inductiveautomation.com/u/Robert.McKenzie)\
**Post date:** [August 20, 2008, 4:31pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783/2 "2008-08-20T16:31:12Z")

</div>

JoshMan,

I have had to deal with something just like this recently. There are special addressing rules for your OPC server that dictate how to read strings. I think that in RSLinx the format is [TopicName]address,SC(length).

For example, if you have a 15 character string starting at n25:4 and the Topic name is “PLC1”, you would use:`[PLC1]n25:4,SC15` as your item address. This may not be the right format for a ControlLogix processor, but the correct format will be in the OPC help file.

---

<div class="post-metadata">

**Author:** ![JoshMan](https://avatars.discourse-cdn.com/v4/letter/j/a4c791/32.png) [@JoshMan](https://forum.inductiveautomation.com/u/JoshMan)\
**Post date:** [August 20, 2008, 5:20pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783/3 "2008-08-20T17:20:51Z")

</div>

Thanks, but that didn’t work.  
There is no memory location like that with Control Logix. PLus its an array, so would it also need the .DATA[0].SC(length)?

---

<div class="post-metadata">

**Author:** ![Robert.McKenzie](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/robert.mckenzie/32/4134_2.png) [@Robert.McKenzie](https://forum.inductiveautomation.com/u/Robert.McKenzie)\
**Post date:** [August 20, 2008, 5:29pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783/4 "2008-08-20T17:29:44Z")

</div>

What OPC server are you using?

EDIT:

From the RSLinx help files:

[quote]ControlLogix 5550: addressing syntax  
The format for solicited DDE/OPC items for the Logix 5550 processor is as follows:

For globally-scoped tags, use your user-defined tag names as the item names.

For program-scoped tags, use the format of Program:ProgramName.TagName for the item names. For example, if the program name is Power and tag is Output, the format for the item is Program:Power.Output.

The addressing syntax for a ControlLogix String UDT is STRING.DATA,SC# (where # is the number of characters). For example, use STRING.DATA,SC10 to read the first ten characters of STRING.DATA.

The addressing syntax for ControlLogix I/O bits is [Local|Remote]::[I|O].Data/bit. For example: Local:2:O.Data/1.  
[/quote]

---

<div class="post-metadata">

**Author:** ![JoshMan](https://avatars.discourse-cdn.com/v4/letter/j/a4c791/32.png) [@JoshMan](https://forum.inductiveautomation.com/u/JoshMan)\
**Post date:** [August 20, 2008, 6:49pm UTC](https://forum.inductiveautomation.com/t/controllogix-string-type/783/5 "2008-08-20T18:49:36Z")

</div>

Hey Thanks

That worked