Motorized Screen help

tglavin

I have a NI2000 controlling a Draper screen. The system is programmed to tell the screen to start to drop and then 10 secs later to stop. Works like a charm, but...after a few hours of inactivity the screen drops to a point several inches farther than normal.

After a reboot, the screen drops to its normal location. But several hours later the same thing.

Any ideas?

Thomas Hayes

Are you using any diodes to stop any CEMF? also how many relays are you using, 2 or 3? Not sure if this is the only screen height that you want but have you tried to adjust the limit switches to prevent the screen from going down any further?

kbeattyAMX

Disconnect the AMX and trigger the screen manually by shorting the Up and or down with the common. See if you are getting the same results. If so contact Draper for a solution.

PyroGuy

How are you stopping the screen after 10 seconds. As I recall, a pulse on both the UP and DOWN relays at the same time will stop the screen. We have not seen that problem.

I think THOMAS has a good idea - if there is no reason for the screen need to go any lower, why not adjust the limit switches to stop it at that point. Nice thing is that you eliminate the 10 second timing part. If, over time, the motors starts to slow down a bit, you can expect a call to re-adjust to compensate for the slower motor rotation.

John Gonzales

Is the 10 seconds changing or is it the screen position that's changing? In other words, if after the period of inactivity, is the relay still being pulsed for 10 seconds by the NI Master?

--John