Application Case Industrial Automation BU, Delta Electronics, Inc. Case Issued by Applicable to Application of Delta’s Temperature Controller in Analog I/O Conversion (With PID Setting) Solution Center Date October, 2009 Pages 2 DTB/DTC series temperature controller Delta’s DTA series temperature controller only supports platinum RTD or thermocouple input, but not analog input. Therefore, DTA can only be used in standard temperature controller. The analog input function is built in DTB and DTC series temperature controllers, so DTB can be used as a converter for all kinds of analog output (e.g. pressure, flow) devices. It can on the one hand replace the analog input module to obtain the digital value, and on the other hand do constant pressure or constant flow control with the PID operation in the controller. The Entire Delta Control System Pressure control: The pressure meter measures the pressure in the pipe, and the pressure output ranges from 4 ~ 20mA. The temperature controller is then able to detect the current pressure and form a close loop, together with PID operation and achieve constant pressure control. Delta’s DTB series temperature controller is built-in with RS-485 communication, which can offer the pressure and output status of the AC motor drive to the remote PC for monitoring. Flow control: Similar to the pressure control, the flow meter outputs signals to the temperature controller, and the PID operation helps set up the desired opening level of the valve to achieve close loop control. 品質至上 信賴第一 追求卓越 QUALITY RELIABLITY EXCELLENT Application Case Industrial Automation BU, Delta Electronics, Inc. System Efficiency Converting analog value into digital value can be achieved by Delta’s PLC + analog module with human machine interface for monitoring. In some cases requiring only single device, we can use the analog input function in Delta’s DTB series temperature controller to realize the conversion in an economical way. Moreover, the PID setting in the temperature controller is much easier to operate and understand than the PLC. If we need to acquire the digital value converted from the analog one, we can do it easily by the built-in RS-485 communication port in the temperature controller, together with the set upper/lower limit range. There are plenty of temperature alarms built in the temperature controller as well, offering maximum 3 I/O alarms by relay output. Delta’s products utilized in this case: Product Temperature controller Model DTB/DTC Parameter setting 1. Sensor input: InPt=mA4 (4~20m input). When the input is current, it has to be connected with 250Ω resistance. 2. Upper limit: TP-H=100.0 (Displayed as 100.0 when in 20mA input) 3. Lowe limit: TP-L=0.0 (Displayed as 0.0 when in 4mA input) 4. Control method: CTrL=Pid (by PID control) 5. Heating/cooling method: S-HC=HEAT (select heating) 6. Alarm: ALA1=5 (absolute value upper/lower limit alarm) 7. P=100.0; I=0; D=0 8. AL1H=90.0. When PV > 90, alarm 1 will be enabled. 9. AL1L=10.0. When PV < 10, alarm 1 will be enabled. 10. SV=100.0 More information on Delta’s industrial automation products, visit our website: http://www.delta.com.tw/industrialautomation 品質至上 信賴第一 追求卓越 QUALITY RELIABLITY EXCELLENT