# PLC / SCADA standard structures / data types

**URL:** <https://forum.inductiveautomation.com/t/plc-scada-standard-structures-data-types/7980>\
**Category:** Archived Topics\
**Created:** [February 10, 2014, 6:16am UTC](https://forum.inductiveautomation.com/t/plc-scada-standard-structures-data-types/7980 "2014-02-10T06:16:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![pat.stave](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@pat.stave](https://forum.inductiveautomation.com/u/pat.stave)\
**Post date:** [February 10, 2014, 6:16am UTC](https://forum.inductiveautomation.com/t/plc-scada-standard-structures-data-types/7980/1 "2014-02-10T06:16:22Z")

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I’m just starting programming on a rather large process control system (compared to what I’ve been working on before). I therefore feel the need to establish some good standard UDTs for the motors / valves etc.

Does anybody have good examples of the data structures you are using?  
I need to build:

- Automatic valve (feedback in both directions).
- Automatic valve (feedback only in open position).
- Automatic valve (no feedback).
- Motor with stepless speed control and PID control (with bus controlled VFD).

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**Author:** ![zackscriven](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zackscriven/32/7213_2.png) [@zackscriven](https://forum.inductiveautomation.com/u/zackscriven)\
**Post date:** [March 23, 2014, 6:39pm UTC](https://forum.inductiveautomation.com/t/plc-scada-standard-structures-data-types/7980/2 "2014-03-23T18:39:55Z")

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What i/o do you have for the Automatic Valve with no feedback?

I like to start with the most basic device and creating a udt for that and then embed that udt in other udt’s that have more signals, or is an assembly of devices.

EX.

UDT:

\_Run \_HOA \_Fail \_Pump udt \_VFD Speed \_Manual Speed \_VFD udt \_Valve udt \_Flow Meter udt

As far as specifics… That is why you are the integrator, you have the tools to design a udt that will work best for your application.

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<div class="post-metadata">

**Author:** ![pat.stave](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@pat.stave](https://forum.inductiveautomation.com/u/pat.stave)\
**Post date:** [March 26, 2014, 3:40pm UTC](https://forum.inductiveautomation.com/t/plc-scada-standard-structures-data-types/7980/3 "2014-03-26T15:40:19Z")

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Hi Zack,

I have found an open publication for a object structure that I’ve utilized in this project (industrial wastewater filtering / fat flotation and clorine desinfection).  
The structure i have used is UNICOS (UNified Industrial COntrol System) developed by the CERN-team.

Although it uses quite large data structures, i have found it to be extremely flexible.  
What i find smartest about it is that the structure contains a “parameter” object.

These parameters are for example:  
-On/Open feedback present?  
-Off/Closed feedback present?  
-Local drive allowed?  
-Fail safe position open?

Of course these parameters can also be utilized in the SCADA system, which means that i can differentiate the UDT for a valve depending on if the valve has feedback sensors or not.

With only two objects; “Analog” and “ONOFF” i can control all my components; valves (on/off or control), pumps (contactor or VFD driven) etc.

The standard is located here: [ab-project-unicos.web.cern.ch/a … bjects.pdf](https://ab-project-unicos.web.cern.ch/ab-project-unicos/Documentation/UNICOS_objects.pdf)