I was hoping to use the pulse from the upper limit to activate the down x function(and vice versa for the lower limit) the issue is then using the same pulse to deactivate the limit switch until the next limit is reached. This is why I wanted to use two latching relays

 

Here is the basis of an idea using a single dual coil latching relay and a delay timer that generates a short pulse after the time it takes the motor to ramp down. This could be done with two 555 ICs.

1 -- Starting with latch relay in up state and travelling up.

2 -- Up limit pulse. On rising edge of pulse trigger delay timer and send pulse to stop VFD via contact that is closed in up state of latch relay. Set latching relay to down state on falling edge of up limit pulse pulse

3 -- Speed now ramping down.

4 -- Delay timer times out and generates a pulse which is fed to down input of VFD via contact on latching relay that is closed in the down state.

5 -- now moving down.

6 -- Upper limit pulse is generated on the down travel. On rising edge of pulse trigger delay timer and send pulse to stop VFD via contact that is closed in up state of latching relay. This contact is now open so VFD does not stop. On falling edge of up limit pulse the down coil on the latching relay is triggered again. This does not matter.

Les.

 

I was hoping to use the pulse from the upper limit to activate the down x function(and vice versa for the lower limit) the issue is then using the same pulse to deactivate the limit switch until the next limit is reached. This is why I wanted to use two latching relays

To use the pulse to start the slowing at the end of a move the addition of the direction command will make it unique. So "forward plus limit" will cause the slowing sequence but "Reverse plus limit"will enable normal speed in the reverse direction. And since the direction command is already available it is just the addition of more logic. Creating the slowing sequence could use a capacitor discharge to bring the speed setting signal down to zero. Then once zero speed is reached the direction command can be reversed, and the speed signal can start to ramp up.
A big problem is that none of the text on the drawings shown in post #4 is readable, so I have no idea what control connections are available. So possibly you can list those input functions so that we can understand what control inputs are available.

 

On a typical VFD if the forward command is issued and the motor is operating at the set RPM, removing the FOR and immediately issuing a REV command, results in a slowing down at the set decel rate and then ramping up to the set REV rpm.
Max.

 

Hi Max,
If the TS's VFD behaves in that way then just using the up limit switch to pulse the down direction input on the VFD (And vice versa.) should give a very simple solution. The fact that the VFD receives a second down direction pulse as the up limit switch is tripped for a second time on the way down should not have any bad effects.

Les.

 

Hi Max,
If the TS's VFD behaves in that way
Les.

All the ones I have used or come across act this way, I have not used the Lenz, however.
Max.

 

All the ones I have used or come across act this way, I have not used the Lenz, however.
Max.

I made my suggestion based on not being certain that the VFD in discussion has any smarts at all. Which without reading the whole manual we can not know. Reading the manual is the responsibility of the user. I understand what is wanted, and even if the VFD does respond like in post #24 does not mean that the resulting response will be at the rate the TS needs for that specific application.

 

@LesJones
Lenze manual.



Max.