Analog I/O in PLC
Цель: Изучить тему «Analog I/O in PLC» 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
Analog input receives current/voltage and converts to raw code. Module configuration selects range: 4-20 mA, 0-20 mA, ±10 V, RTD/TC depending module. Wrong configuration causes offset or saturation.
Analog output converts digital command to current/voltage. Signal quality includes underrange/overrange, wire break detection where supported and diagnostic bits.
Grounding/isolation
Some modules have isolated channels, others share common. Field loop design must match. Combining grounded source and grounded input incorrectly can create loop current paths.
Практическая работа
For pressure transmitter 4-20 mA to AI and valve positioner 4-20 mA from AO, draw complete current loops including supply and commons.
Самопроверка
• Why configure AI range?
• What is raw code?
• How AO controls valve?
• Why channel isolation matters?
• What diagnostics can analog module provide?
Что нужно запомнить
- Analog input receives current/voltage and converts to raw code.
- Module configuration selects range: 4-20 mA, 0-20 mA, ±10 V, RTD/TC depending module.
- Analog output converts digital command to current/voltage.
- Signal quality includes underrange/overrange, wire break detection where supported and diagnostic bits.
- Some modules have isolated channels, others share common.