Hello everyone,

I have little problem.I use S7-300 with FM353 in order to move an axis in reference point. I also use two limit switches and one BERO(proximity switch).
The problem is that when i give direction for example to move right and the reference point switch is to the left the axis goes to the right limit switch and stops.
How is it possible to control the harware limit switches through the program in order to make Ref point approach from every position(touching the HW limit switch and going back to the REF point switch)?

Please help

Thanks,
Mpam-Mpam

18 K Type of reference-point

approach

(reference-point approach

direction)

0 0 = direction + current-sourcing

pattern zero or zero pulse

external to right of RPS

1 = direction + current-sourcing

pattern zero or zero pulse

external to left of RPS

2 = direction - current-sourcing

pattern zero or zero pulse

external to right of RPS

3 = direction - current-sourcing

pattern zero or zero pulse

external to left of RPS

4 = direction +, RPS center

8 = direction +, RPS edge

9 = direction −, RPS edge

Thx again

Here is the wire connection of the FM 353:

On input 3(pin) i have the RPS connected(DI 1)
On input 4(pin) i have the Left hardware limit switch(DI 2)
On input5(pin) i have theRight hardware limit switch(DI 3)

In the machine data i declare DI 1 as Reference point switch and
DI 2,3 as reversing switches for Ref point.
When i declare both DI 2,3 i get an error. When i only use one of them it works normally.Could it be because the FM 353 can only control one reversing switch?
I hope this time i've made it more clear.

Thanks
mpam-mpam

Could it be because the FM 353 can only control one reversing switch?