NEW PLC tutorial and guides for automation

hi there, this blog is dedicated to provide you with PLC tutorial specifically for industrial automation and robotics.



There are two types of PLC available in the market, which is relay type and transistor type. the major difference between these two is the response time. The response for transistor type PLC can go as fast as 0.5 microsecs compared to those of relay types which have response time around 10 ~ 20 millisecs.

The ability of transistor type PLC to do fast switiching makes it possible for it to have pulse outputs and high speed input to control AC servo motor.

long term timers

Example 1:
Long-term Timers
The following program examples show two ways to create long-term timers
with standard TIM and CNT instructions.
Two TIM Instructions
In this example, two TIM instructions are combined to make a 30-minute
timer.




TIM and CNT Instructions

In this example, a TIM instruction and a CNT instruction are combined to make a 500-second timer.TIM 0001 generates a pulse every 5 s and CNT 0002 counts these pulses. The set value for this combination is the timer interval × counter SV. In this case, the timer SV would be 5 s x 100 = 500 s. With this combination, thelong-term timer’s PV is actually the PV of a counter, which is maintained through power interruptions.