What is the difference between the on-delay timer and the keep-alive timer in Siemens PLC?

Difference:

1. Definition:

On-delay timer: The on-delay timer is the most common and basic timer in various PLCs. This timer is called SD timer in SIEMENS PLC.

Hold-type on-delay timer: This timer generates a latch function when the input condition 00000 is ON, even if the input condition 00000 becomes OFF, the input condition is still ON, when the current value of the timer When it is equal to the set value, the timer operates. This timer is called SS type timer in SIEMENS PLC.

2. Effect:

The on-delay timer means that after the two ends of the business circle are connected, the contacts are not connected immediately, but only after the delay time.

Keep-alive timer is a timer means that after the two ends of the industry circle are connected, the contacts are connected immediately, and only after a certain time, they are disconnected.