ENCODER/PLC INTERFACE
ENCODER/PLC INTERFACE
(OP)
I HAVE AN APPLICATION I COULD USE SOME HELP WITH. I HAVE A VERITCAL CARRAIGE THAT TRAVELS 90 INCHES CARRYING APROX. 35 lbs. I HAVE TO STOP THE CARRAIGE AT 18 DIFFERENT POSITIONS AND TRAVEL AT 6 INCHES/SEC IN ONE DIRECTION AND TRAVEL AT 12INCHES/SEC AT THE OTHER. I NEED TO INFERFACE POSITON DATA WITH A MICRO PLC. THIS IS A STACKING OPERATION SO AT EACH POSITION THE PLC HAS TO FIRE SOME OUTPUTS. I'M LOOKING FOR A
LOW COST WAY TO CONTROL THE SPEED OF THE MOTOR AND ASLO GET POSIOTN DATA. CAN ANYONE POINT ME IN THE RIGHT DIRECTION?
LOW COST WAY TO CONTROL THE SPEED OF THE MOTOR AND ASLO GET POSIOTN DATA. CAN ANYONE POINT ME IN THE RIGHT DIRECTION?





RE: ENCODER/PLC INTERFACE
You can do this type of application with any micro/brick plc that has a HSC (high speed counter) circuit build in or a discrete circuit that can handle over 20hz (it's also scan time dependent when using a discrete input as a counter above 20hz.) The input requirement would be a quadrature incremental encoder. You could also use a dicrete input like a proximity if your application allowed for it.
www.automationdirect.com
www.keyence.com
www.omron.com
Another possibility would be a PLS (programmable limit switch) and a resolver.
http://www.patriotsensors.com/Programmable_Limit_Switch.html
http://www.toledotransducers.com/pls.htm
http://www.ciecocontrols.com/limits.htm
Hope this helps some,
Carl
RE: ENCODER/PLC INTERFACE
This sounds like a motion control/servo application. What type of motor do you have? How are you going to control the speed of the motor?
A servo system consists of a motor, an encoder on the motor shaft and an amplifier (Drive). The encoder connects directly to the drive, and the positioning error is calculated by the drive. You can get high torque and high speed combinations.
The drive will usually have a buffered encoder connection for use with any external control. It will also have I/O, so connection to a PLC is usually not required.
Price of a motion control system is proportional to:
Accuracy required
Speed required
Tourque required
Bandwith (or response time)
Good Luck!!!
RE: ENCODER/PLC INTERFACE
Depending on the motion transducers You have, you can choose the right interface module, to control the position and the speed. You can find also the right operator panel to configure and to watch the entire process.
What kind of motors do You use? A step-by-step one it would be very easy to control
RE: ENCODER/PLC INTERFACE
RE: ENCODER/PLC INTERFACE
RE: ENCODER/PLC INTERFACE
RE: ENCODER/PLC INTERFACE
http://oeiweb.omron.com/oei/
RE: ENCODER/PLC INTERFACE
My motor is 20 HP DC. It needs to drop a part @ 1700rpm for 210", then change speeds to 500rpm and drop 36" all in 7 seconds.
We are using an AB1397 DC drive, to control speed/direction. A 180PPR pulse encoder hooked up to a 6 setpoint batch counter. The batch counter sends 24VDCinputs to a SLC5/04. The slc contols the DC drive by contact closure. No costly analog i/o needed.
My solution although not sophisticated, is cost efective, easy to confugure, and reliable.
Red Loin Industries makes good inexpensive Batch counters.
I hope this is some help!
Good luck
John McCann
RE: ENCODER/PLC INTERFACE
Try using a PLC with a high speed counter/stepper motor controller. Allen-Bradley SLC has one for example. Also Koyo (automation direct has one). The HS card outputs to a stepper motor controller which moves your table.