If you want to understand this project so easy you could have learnt Configuring for first time PLC S7-1200 Siemens and Also Configuring and Programming Analog Inputs 4-20mA in S7-1200 Siemens

PROJECT OBJECTIVE

The Project start as "Experiment" and we want to Dry the Waste that comes from a Wastewater Treatment Plant.....but what means it?

All the waste from Wastewater Treatment Plant must to be in Temperature for his dried and after "Reuse" for other purpose; it means this project search Dry into a "Greenhouse" that inside the Temperature is higher than Outside, is if higher you think it dries faster? but remember you have some other points to consider:

• The waste that will store is Relatively Toxic, for this reason we will have some toxic gases inside our Greenhouse, in this case Ammonia-NH3; Hydrogen Sulfhidric-H2S ; Volatile Organic Compound-VOC


• Inside a Greenhouse there are always 2 importants parameters; Humidity (%) and Temperature (°C)


• The Projects include Electromechanical Devices as Extractors, Fans, Automatized Windows, Gate Motors, and Signal Security Devices

ENGINEERING INFORMATION

All the projects always may be of better features, in this case is a "Pilot Experiment Project" it means is a experiment that works a team of Engineers, Safety, Chemicals, etc; it means the Project of Instrumentation must to be Friendly and easy to operation with all Professionals, the configuration that we design is very important for the project

Important Engineering Documentation

• Power Electrical Layout
• Electrical Control Layout
• Instrumentation and Connections Layout
• Technical User Manual
• PLC Programming
• SCADA-HMI Programming
• Start Final Project

CHOISING DEVICES

As in all Control Projects, Choose the best PLC is always a challenge because you must to consider the Price, Difficult, Reliability, etc, Remember Learn to Choose a PLC for this project we choose PLC S7-1200 Siemens; WHY? Robust, Reliable, Normal Software and Enough for this project

The final Electromechanical Signals are:

• 8 Digital Inputs
• 12 Digital Outputs
• 14 Analog Inputs 4-20mA
• 1 Touchscreen HMI Weintek (Ethernet)

Always must to be clear in know all the Electrical Control elements as:

• Circuit Breaker One-Phase and Three-Phase
• Contactors and Electromechanical Relays
• Motor Safe Proteccionts as Thermal Overload Relay or Phase-Out relay
• Pushbuttons, Switch, Limit Switchs

First we draw the first Layout of POWER recognizing all motors and loads, powering by electric supply, very important

Download Electrical Power Layout (PDF)

Electrical Layout of Power Instrumentation Project

Next begin to design the Electrical Control System

Download Electrical Control Layout (PDF)

Electrical Layout of Control Instrumentation Project

In All Electrical Projects is very important draw the distribution of Power Loads

Download Distribution Power Layout (PDF)

Distribution Power of Loads Layout

The Information we have seen in this moment now is more clear; we know the elements, the objective, Devices, we are ready to create engineering

DEVICES AND PARAMETERS

First we identify most important variables and parameters to measure in the process:

• Temperature - °C
• Humidity - %H
• Ammonia (NH3) - PPM
• Hydrogen Sulfide (H2S) - PPM
• Volatile Organic Compounds (VOC) - PPM

Now is very important always have in consideration before choose an Instrument technical features of the enviroment:

• Enviroment Temperature: The Maximum Temperature (°C) that the Sensor must to work
• Humidity: The Maximum Humidity (%) that the Sensor must to work
• Hermetic Sealed: Always is better protect a Sensor from Water or Rain
• Dust or Garbage: Sensors must to be protected against Dust is very important consider IPxx Code; if these conditions are not considered, Sensors may have fails

CHOOSE PLC

The final information we have obtained let's define:

• 8 Digital Inputs
• 12 Digital Outputs
• 14 Sensors Transmitters 4-20mA
• 1 HMI Touchcreen Weintek (Ethernet)

BUT we can see our PLC have all Digital Outputs used, So we add a Module Relay Outputs to the PLC... remember to see in details Learn to Choose a PLC Here, the PLC we have choosed and the Modules may looks like this:

Download Architecture PLC Layout (PDF)

The final Hardware choosed for this project is:

• 1 CPU 1214 DC/DC/Relay Siemens S7-1200
• 2 Analog Inputs Module 4-20mA SM1231 8CH
• 1 Relay Outputs Module SM 1222 8CH

CONTROL CONNECTIONS

One of the most complex points is understand 100% the connections of all the Process; so we have to define:

• Motors: All Loads 0-1 are activated by Digital Outputs
• Slide Gate Motor: The wire is like the User Manual Shows and consider in PLC Module
• Transmitters: Ambos Sensores se cablean según Fabricante del Sensor/Transmisor
• Digital Inputs: The most easy to wire; Fails Thermal Overload, Pushbuttons, Emergency Stops, etc

Download Complex Connections Layout (PDF)
Connections Sennsors - PLC - Control Systems

Wire and Connections of Transmitters / Sensors by Manufacturer

Typical Sensors Wire Diagram 2-3-4 Wires in Analog Input Module AI S7-1200

Remember you can learn from 0 Learn for first time PLC S7-1200 and if you want to be smarter Scale and Activate Analog Inputs in 4-20mA in PLC S7 1200

Them choose the Right CPU 1214 in this case and begin to configure:

Add the IP to our CPU

Add the Expansion Modules Analog AI SM1231 and Output Relay SM1222 to our CPU

In this case gonna work with Transmitters 4-20mA; So we gonna configure All Analog Inputs of the Analog Modules in Current 4-20mA

Other point VERY IMPORTANT; Configure with order the Sensors in both Modules Added; in this moment and with all information watched, we must to be clear in what we are doing

Digital Inputs and Outputs in CPU and Module DO Relay looks like this:

SCALE SENSORS

Other very important point is Scale Correctly the Sensors/Transmitters, this point is very important if we want that the project will be an success!

The Draeger Transmitters must to be configured for Specialists (in Transmitters), Reason? They make real test with Gas NH3; H2S & Covs; Control Engineer Scale and Configure in PLC and by other side Draeger Specialist configure and test from Transmitter

First start to Normalize NORM and then to SCALE for more details Scale Analog Inputs 4-20mA in PLC S7 1200

Now that we have the information in orden begin to create the variables SCALE and NORM for each of our 14 Sensors/Transmitters

Finally Normalize and Scale all Sensor 1 for 1; remember the Range Measurement:

• Temperature: -20°C - 80°C
• Humidity: 0 - 100%
• Ammonia NH3: 0 - 300 PPM
• Hydrogen Sulfhidric: 0 - 50 PPM
• Volatile Organic Compounds: 0 - 50 PPM

Scaling Ammonia Transmitters NH3-1 and NH3-2 in 0-300 PPM


Scaling Hydrogen Sulfide H2S-1, H2S-2; COVs-1, COVs-2; both in 0-50 PPM


Scaling 4 Sensors of Temperature in -20 - 80°C


Scaling 4 Sensors of Humidity in 0 - 100%

Until the moment we have worked and Scaled the 14 Analog Sensors, it's time to Monitoring in SCADA by a Weintek HMI Touchscreen MT8070iE

EXPORT Tags: from TIA PORTAL

Now go to Easybuilder Pro Software, if you don't have installed this Software is FREE How Download and install Software HMI Weintek Easybuilder Pro

Select the PLC S7-1200 Siemens and assign SAME IP 192.168.0.2 that we configure our CPU from TIA Portal (Step 4)

This is the moment for IMPORT TAGS that we before Export from TIA PORTAL

MONITORING SENSORS

Insert the blocks NUMERIC; here is the Configuration to Monitoring AI, IMPORTANT You must to select the FINAL SCALED VALUE For each one of the 14 Sensors

Configure the information, the importan is "Decimals or Integers"; for NH3 is 0-300 and must to consider 3 Digits; and for other 2 Sensors 0-50 we configure 2 Digits

Example of Configuration of Sensor H2S with TAG ADDRESS and Format

Finally to design our SCADA Add our 14 Sensors and we can write in Screen for recognize it

COMPILE and SIMULATE OFF LINE, we can see our 14 Sensors in HMI, remember the value showed is the "Final Scaled Value" from PLC S7-1200

ELECTRICAL LAYOUT POWER & CONTROL

• General Diagram Electrical Power


• Distribution Electrical Loads


• Wire and Connections Control Systems


• Diagram Instrumentation Cabinet


• Distribution of Instruments and Equipments


• Details Design Cabinet Instrumentation Layout


• Connections and wire Complex of process


• Architecture of PLC S7-1200 Siemens

DOCUMENTS & USER MANUAL

• User Manual (Spanish)


• Technical and Information Document (Spanish)