Technical Survey to develop an Automated Solution with PLC.
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A technical survey for a PLC (Programmable Logic Controller) project is the fundamental process of gathering information, observing the process in the field, and documenting the industrial process that is to be automated or improved. Its objective is to understand the step-by-step operation, document the current state ("AS-IS"), and define the actual needs to avoid design errors, excessive costs, or failures during implementation.
This process consists of the following key activities:
- 1. Definition of Context and Objectives.
- • Process Identification: Understand which machine or production line will be automated (conveyor belts, motors, industrial arms).
- • Set Goals: Define whether the project seeks to improve efficiency, security, or update an old system.
- • Interviews with Operators: Document how current activities are carried out and common problems in the process.
- 2. Data Collection in the Field (Physical Survey).
- • Input Identification: List sensors (proximity, temperature, level, pressure), pushbuttons, switches, and limit switches.
- • Identification of Outputs: List contactors, solenoid valves, variable speed drives, pilot lights and alarms.
- • Signal Type: Determine if they are digital (ON/OFF) or analog (0-10V, 4-20mA).
- • I/O Count: Create a spreadsheet (Excel) detailing the total number of inputs and outputs required.
- 3. Infrastructure and Hardware Survey.
- • PLC Selection: Identify the brand, family, and capacity of the processor, as well as any necessary expansion modules.
- • Space Assessment: Check the space in the electrical panel to place the PLC and its peripherals.
- • Industrial Communications: Identify existing or required communication protocols (Ethernet/IP, Profinet, Modbus) for HMI/SCADA.
- • Physical Environment: Evaluate conditions such as temperature, humidity, or electromagnetic interference that may affect the PLC.
- 4. Analysis of the Operation Sequence.
- • Flowchart: Document the logical sequence of the machine (what step must occur before another).
- • Safety Conditions: Identify emergency stops, interlocks, and safety sensors.
- • Manual/Automatic Operation: Define how the machine will operate in both modes.
- Survey Results.
- At the end, a technical report must be available that includes:
- 1. I/O List.
- 2. Electrical plans or sketches.
- 3. Functional description of the process.
- 4. Hardware and software requirements (firmware, cybersecurity).
This survey avoids having to guess the system's needs and allows for accurate simulation or programming.
- DATA:
To successfully implement a PLC (Programmable Logic Controller)-based control system, it is essential to gather detailed information before beginning programming or purchasing hardware. This stage is known as:
- Functional Specification.
Here is the critical data you should collect, organized by category:
- 1. Definition of the Process and Sequences.
- • Description of operation: What the machine or process should do (automatic, manual, semi-automatic cycles).
- • Flowchart or logic: Step-by-step logical sequence (e.g., step 1: open valve A, step 2: turn on pump when level is X).
- • Safety conditions (Interlocks): What actions should stop the process or prevent it from starting (emergency stops, motor protectors, safety sensors).
- • Failure states: What to do if a sensor fails or an action is not performed within the expected time.
- 2. Inputs and Outputs (I/O - Input/Output).
You must create a comprehensive list of all field devices connected to the PLC.
- • Digital Inputs (DI): Pushbuttons, switches, proximity sensors (limit switches), photocells, relay contacts.
- • Analog Inputs (AI): Temperature, pressure, flow, level sensors (4-20mA, 0-10V signals).
- • Digital Outputs (DO): Contactor coils (motors), solenoid valves, pilot lights, relays.
- • Analog Outputs (AO): Frequency converters (speed), valve positioners.
- • Operating voltages: Determine if the signals are 24VDC (industry standard) or 110/220VAC.
- 3. PLC technical specifications (Hardware).
- • Amount of I/O: Total inputs and outputs required (consider an extra 20% for future expansions).
- • Processor Type: Required processing speed (for fast or slow processes).
- • Memory: Program memory size (for very large codes).
- • Expansion capacity: Does the system need additional modules in the future?
- 4. Communication and Networks.
- • Protocols: Does the PLC need to communicate with other devices? (HMI, SCADA, drives, other PLCs). Examples: Ethernet/IP, PROFINET, Modbus TCP/RTU, Profibus.
- • Connectivity: Required ports (RJ45, RS485, USB).
- 5. Operating Environment (Assembly).
- • Environmental conditions: Temperature, humidity, vibration, dust or presence of corrosive gases to choose the enclosure and PLC protection.
- • Power supply voltage: 110VAC, 220VAC, 24VDC.
- 6. Human-Machine Interface (HMI).
- • Data to be displayed: Variables that the operator needs to see (temperature, speed, machine states).
- • Data to be entered: Setpoints, recipes, times.
- Workflow Summary:
- 1. Understand the process ->
- 2. List I/O ->
- 3. Design Logic/Security ->
- 4. Select Hardware
- 5. Schedule.
- Additional Requirements:
- List of processes.
- List of procedures.
- List of machinery.
- List of machines.
- List of systems.
- List of departments.
- List of personnel.
- Customer list.
- List of roles.
- List of production lines.
- List of production plans.
- List of main faults.
- List of current problems.
- List of losses.
- List of kpi's main departments.
- If you are not yet convinced about purchasing our product, service, or course, we can conduct a technical assessment at your facility to provide greater clarity and precision regarding the scope of the report we deliver. This assessment costs USD $60,000.00 and will be carried out over two weeks at your location. This fee will be refunded upon purchase of the product, service, or course; otherwise, it will not apply.
- Technical Assessments: Service Description.
- We offer these options to clarify the technologies.
- Courses for:
- Executives.
- Beginners.