Hydraulic Robot With Gears

Hello, everyone I'm new to this put from what i've seen here you guys know your stuff. I'm in college learning about Automation systems, and I have a hydraulically operated robot with gears (that have limit switches, to act as primative encoders i assume). What I am curious about is, once write the program how should i go about controlling its position? Since everytime each gear moves, it sends the false to true signal via limit switch to a PLC, should i use a squencer or shift regisiter? There are only 32 teeth on these gears, also. I've got a fair amount of programming experience in RSLogiX 5 and 500. Any suggestions would be awesome, since i am perplexed at the moment! Thanks

Don

Encoder signals are generally sent into counters. Depending on how fast the on/off transitions are happening, you may need a special input card called a high speed counter.

Another consideration is whether or not you can tell direction from the signals. If you have two pickups that have the right phase relationship, you can tell which way you are going and can do a count up or count down.

That should be enough to get you started and off on some google searches.

Good Luck

So the gear RPM and position (relative to a home position) can be obtained from limit switches counting gear teeth?

Just one switch per gear?

How fast can gears rotate? Thus how many pulses per second from the limit switch on a gear?

Dan Bentler

Does it have a zero position or a home position sw or sensor?
If so I would use a counter to increase / decrease the position according to the rotation. You have to know the direction as Norm said. Use the home or zero position to zero the position.

If you have 2 sensors and can set them up to read 90 degrees out of phase. You can get 5.625 degrees per increment if you only have 1 you will get 11.25 degrees. If you get very fancy in logix you can count the 4X

My guess is the this is a school so it will be a slower system.