1 / 17

ECT 464

ECT 464. Lecture 4b Special Functions. Special Functions. One Shot (ONS) (OSR) SLC500 triggers a one time event activates on false to true transition rung must go false again to reset allowed to use one OSR per output in a rung do not place input conditions after the OSR

tale
Download Presentation

ECT 464

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. ECT 464 Lecture 4b Special Functions

  2. Special Functions • One Shot (ONS) (OSR) SLC500 • triggers a one time event • activates on false to true transition • rung must go false again to reset • allowed to use one OSR per output in a rung • do not place input conditions after the OSR • uses a bit location to store last state

  3. Special Functions • One Shot Rising (OSR) • triggers a one time event • activates on false to true transition • rung must go false again to reset • allowed to use one OSR per output in a rung • do not place input conditions after the OSR • uses a bit location to store last state • Activates output bit

  4. Special Functions • One Shot Falling (OSF) • triggers a one time event • activates on true to false transition • rung must go true again to reset • allowed to use one OSF per output in a rung • do not place input conditions after the OSF • uses a bit location to store last state • Activates output bit

  5. Special Functions • Label (LBL) • Target of jump instruction • Must be first instruction of rung • 256 labels in each subroutine (SLC) • 1000 labels in each subroutine (M1000)

  6. Special Functions • Master Control Reset (MCR) • Acts on rungs between start and end fence • When off, ignores inputs, and de-energizes all outputs in the zone • When on, inputs and outputs treated normally • Latches, retentive timers, and counters remain in their last state • Must end zone with unconditional MCR • Cannot nest MCR’s • Always place MCR as last instruction on rung

  7. Special Functions • Jump (JMP) • When true, skips to the rung with the LBL instruction and continues executing • When false, doesn’t do anything • Can jump forward and backward • Can jump to the same label from several JMP instructions • Do not jump into a MCR zone • Not between program files

  8. Special Functions • Temporary End (TND) • Stops processor from scanning the rest of the rungs • Used to debug a program • Used to stop the execution of part of a main program or subroutine

  9. Special Functions • Suspend (SUS) • Sends PLC into idle mode • All outputs de-energized • Used with Suspend ID number

  10. Special Functions • Subroutine (SBR) • Marks the beginning of a file • Optional use

  11. Special Functions • Jump to Subroutine (JSR) • Used to execute a subroutine and then return • Saves memory • Nest 8 levels deep • File number 3-255 (SLC or M1500) • File number 4-15 (M1000)

  12. Special Functions • Return (RET) • Marks the end of a subroutine • Can be conditional (SLC) • Optional Use (END works as well) • Can return a value (SLC)

  13. Special Functions • End (END) • Marks the end of a file

  14. Special Functions • Immediate Input with Mask (IIM) • Update data prior to normal scan • Mask of 1 passes • Specify input word • Embedded I/O only

  15. Special Functions • Immediate Output with Mask (IOM) • Update outputs prior to normal scan • Mask of 1 passes • Specify output word • Embedded I/O only

  16. Special Functions • I/O Refresh (REF) • Executes a new I/O scan in middle of execution • Can also do communications

  17. Next Class • I/O Scans and memory layout • PLC Modes

More Related