Transcription of Chapter 7 TIMERS, COUNTERS and T/C APPLICATIONS
{{id}} {{{paragraph}}}
Example: dental hygienist
Chapter 7 TIMERS, COUNTERS and T/C APPLICATIONS
Ch 7 Timers, COUNTERS , T/C APPLICATIONS 1 Chapter 7 TIMERS, COUNTERS and T/C APPLICATIONS Introduction Timers and COUNTERS are discussed in the same Chapter since most rules apply to both. Timers and COUNTERS have been in existence for as long as relays and provide an important component in the development of logic. Timers were constructed in the past as an add-on device to relays slowing down the transition of the plunger from immediately opening or closing. The time delay was accomplished with a pneumatic bladder that allowed the air to escape either quickly or slowly depending on the setting of the timer. Quick was usually less than a second and slow was usually between 30 and 60 seconds. Setting this kind of timer was an inexact science and today's traffic lights are an example of the fickle nature of timers that seldom respond in exactly the same from day to day and year to year.
specify whether the IEC timer is stored in its own data block (single instance) or as a local tag (multiple instance) in the block interface. ... P T P T Th e s e fig u re s s h o w p u ls e d ia g ra m s o f th e G e n e ra te O ff-De la y in s tru c tio n : Fig. 7-8 Off-Delay Timer Timing Diagrams . Ch 7 Timers, Counters, T/C Applications 8 ...
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: