Device Modeling

Equivalent Devices

For devices of the same type, do you use the same code?

1. Can equivalent devices be configured as an array of structures?
2. Do you have an independent I/O mapping routine that assigns physical hardware to these devices?
3. Do you have an independent or parent routine that interconnects these devices?
4. Do you have an independent or parent routine that handles alarm assignment and processing?

Tag Management

Tag Organization

Do you use Excel or other tools to generate tag lists and PLC code?

1. Do you maintain a complete list of accessible tags that can be filtered for:
   • I/O mapping
   • HMI connections
   • Alarm triggering
   • Initialization
   • Historization
2. Are variables initialized during the PLC first scan?
3. Do you use always the same name for a particular device?
   1. Blower_Motor1, Blower_M1, BlowM1

Programming Practices

Structured Text Usage

Do you prioritize Structured Text over Ladder Logic when appropriate?

1. Do you limit Ladder Logic to simple operations and short tag names (for example, less than 30 characters)?
2. Do you use AI tools to automate code generation and repetitive programming tasks?
3. Do you minimize the number of function or AOI parameters by using structures (UDTs) instead of individual tags?

Maintainability

1. Is device functionality encapsulated in reusable functions, function blocks, or AOIs?
2. Can a new device be added with configuration only and no code changes?
3. Are alarm, HMI, and I/O interfaces separated from control logic?
4. Can the application scale from 1 device to 100 devices with minimal additional code?

Scoring

• Yes = 1 point
• No = 0 points

Score:

• 0-5: Traditional programming approach
• 6-10: Moderately reusable architecture
• 11-15: Advanced modular architecture
• 16+: Highly scalable and maintainable architecture