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DDC controller for HVAC

Thread Starter: hieutran8969   Started: 4/4/2013 6:06 AM   Replies: 3

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  4/4/2013, 6:06 AM
Joined 11/17/2011
Last visit: 1/27/2015
Posts: 82
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Rated: Excellent [5 out of 5 / rated 1 time(s)]. (1) 
dear all,

i chose some DDC controller for HVAC, this is the first time i do it. So can you send me some catalog about DDC controller of siemens for HVAC?

And can i use PLC to replace DDC controller? i dont know what is advantage of DDC controller?

thanks in advance,
  4/26/2013, 9:03 AM
Joined 6/4/2010
Last visit: 1/27/2015
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Dear forum member,  

DDC stands for Direct Digital Control and is the automated control of a condition or process by a digital device. DDC is often used to control HVAC (heating, ventilating, and air conditioning) devices such as valves via microprocessors using software to perform the control logic. This is very similar to a PLC (Programmable Logic Controller).  Both are normally free programmable and both communicate with other devices via a communication bus system.  
Easy speaking you can say that the DDC is for the Building Automation what the PLC is for the Industry Automation.
DDC controllers for HVAC are normally delivered with specific application libraries for HVAC control. Also they often provide an open bus system, e.g. like BACnet (
Data Communication Protocol for Building Automation and Control Networks)  
The Desigo Building Automation System is the main Siemens range for HVAC and Building Automation.  You can find the “Desigo PX - Automation system for HVAC and building services” – System description under the following link: 

Please note that Siemens has a very wide range of control product for any requirement and type HVAC application. Other controller or control products can be found in the product catalogue: 

The HVAC Integrated Tool (HIT) may help you to select the right controller or periphery device, just select your application: 

Please contact your local Siemens BT sales organization for further information. They are glad to help you! 

Best regards,
Thank you for this post from:
  5/26/2014, 7:08 AM
Joined 6/8/2013
Last visit: 12/19/2014
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DDC controller is cost effective & it is design for HVAC system. 
It is possible to use plc  to control HVAC system. but for that wants smart devices to communicate with plc.
also you have to write program to control your hvac system. For monitoring  you have to develop HMI or SCADA. .
  5/26/2014, 4:32 PM
Joined 10/10/2010
Last visit: 1/9/2015
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it's a very good system and smart controller for controlling HVAC systems as it's flexible and durable for more applications. you can communicate with HMI for all system control 
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