Electrical installation and loop checks
Цель: Изучить тему «Electrical installation and loop checks» и закрепить её практическими заданиями и самопроверкой.
2 акад. часа чтение и разбор теории, решение задач, работа со схемой или виртуальным стендом и проверка понимания.
Основной материал
Verify supply voltage/polarity, cable continuity, insulation where applicable, shield/ground, terminal numbers and segregation. Loop check proves signal from field to control system and back for outputs.
End-to-end test
Simulate transmitter 4, 12, 20 mA and verify HMI 0, 50, 100 %. Then issue output command 0,50,100 and verify valve/positioner or AO current.
Wrong scaling
End-to-end test catches reversed range, wrong units, tag mismatch and channel assignment before startup.
Практическая работа
Create loop check sheet for one AI and one AO with columns Field Injection, Field Reading, PLC Raw, PLC EU, HMI, Expected, Pass.
Самопроверка
• What is loop check?
• Why test multiple points?
• What catches end-to-end?
• Why verify polarity?
• What is channel assignment error?
Что нужно запомнить
- Verify supply voltage/polarity, cable continuity, insulation where applicable, shield/ground, terminal numbers and segregation.
- Loop check proves signal from field to control system and back for outputs.
- Simulate transmitter 4, 12, 20 mA and verify HMI 0, 50, 100 %.
- Then issue output command 0,50,100 and verify valve/positioner or AO current.
- End-to-end test catches reversed range, wrong units, tag mismatch and channel assignment before startup.