conveyor - PLC Programming & Automation

RFID PLC Integration: Read and Write Tags from Ladder

Timing chart of an RFID read cycle: the trigger bit, the reader busy bit, the done bit, and the UID landing in the UDT before the trigger is cleared

Pick HF or UHF, connect the reader over EtherNet/IP or Modbus, map the data into a UDT, and run a trigger, busy, done handshake that does not drop reads.

PLC Sustainable Manufacturing: Measure, Then Shut Off

by PLC

Timing chart of idle shutdown and staggered restart: part flow stops, the idle timer completes five minutes later, the conveyor, vacuum generator and extraction fan switch off in sequence, and when parts return the fan starts first, then the vacuum, then the conveyor

Meter energy, air, water and scrap per part, write idle shutdown in Structured Text, stagger the restart, and report numbers that survive an audit.

PLC Conveyor Control: Zone Logic, Jams and PowerFlex

by PLC

Ladder rung for a conveyor zone: the line running bit, the zone photo-eye blocked, the downstream photo-eye clear and no jam latched, driving the zone run request

Zone accumulation, cascade start and stop, jam timers that do not nuisance trip, and driving a PowerFlex 525 over EtherNet/IP from a CompactLogix.

Count Down (CTD)

by PLC

The CTD instruction counts downward each time the rung-condition-in transitions from false to true. Ladder Diagram Operand Data Type Format Description Counter COUNTER tag Counter structure Preset DINT immediate Value of Counter.PRE. Accum DINT immediate Value of Counter.ACC. COUNTER Structure Mnemonic Data Type Description .CD BOOL The countdown enable bit contains rung-condition-in when the instruction … Read more