create free wheeling timer with s7 300 s_pulse timer

[sLayER69]

i am new at siemens plc . i used to work with AB plc where timers were very easy. Here i am confused with s7 timers. i want to create free wheeling timer where timer will reset by it self after preset time and start again. In AB timers u get DN bit here i dont know.

 

[mk42]

Generally, you should use the IEC style style timers, where it uses an FB concept. The S5 style timers are generally considered to only exist for backwards compatibility.

If you're using Simatic Manager, you'll find them in the standard library (system function blocks), down below the basic instructions.

 

[JBA-DK]

You could use one of the special memory bits that goes on and off continually

 

[cardosocea]

You're not in Kansas anymore...

When you configure your PLC there usually will be something like memory clock tick box and then you select which memory byte will have a running clock implemented.

Here's a bit more info on this:

http://www.plctalk.net/qanda/showthread.php?t=28282
https://support.industry.siemens.co...ulse-in-step-7-s300/128474?page=0&pageSize=10

This probably has something to do with the fact that Siemens PLC's are more like actual computers than glorified relays in a nice box.

 

[ivo.maenen]

If you want to change the on- and off-time:

AN T1
L S5T#2s
SP T0

AN T0
L S5T#1s
SP T1
= Q0.0

 

[sLayER69]

i did it

A I 0.0
AN M 0.1
L S5T#5S
SP T 0
NOP 0
NOP 0
NOP 0
A T 0
= Q 0.0

AN Q 0.0
FP M 0.0
= M 0.1