Rotary encoder - NI6602

[ree]

Has anyone run a RLS RM22 rotary encoder (RM22 non-contact 5 V, http://www.rls.si/default.asp?prod=rm22) into LabVIEW? I have a NI6602 counter card to connect the encoder to.

I need to ascertain if the shaft is rotating at a constant speed or slowing down and speeding up during a revolution. Before I buy the RM22, I wondered if anyone had any suggestion or recommendations on the easy way to do this. Thanks.

[CCornish]

You can set the counter/timer cards to measure frequency and use the A or B outputs from the encoder (if the encoder is incremental type) to generate the pulses to measure.  This way you can measure the speed at which the pulses are occuring.  If you want to measure RPM, then you would want to use the Z output (again, if the encoder is incremental type) because it will pulse when the encoder has rotated 360 degrees.  You can perform a simple running average to determine RPM and/or speed.

[J POWER]

Hi,

To check the shaft rotation, you would handle that within your code, by checking to see if the number of increments in the first 90 degrees is equal to the number of increments in the second 90 degrees, and moniter the time taken for the shaft to move, as long as you know the speeds of the motor and the number of increments the encoter is likely to produce you wil be able to set up the hard ware corretly. I.e sample rates and timing of the loops.

what kind of changes are you trying to see. full RPMs or fractions of a RPM?

Hope this helps