ML1500 Cam Switch

[lynchmob 0]

Hello all, I have used encoders with micro1500's before using the high speed counters on the base unit. But now I have to fire a bunch of outputs on and off based on encoder position (like a cam switch). The HSC instruction only has one set of presets, so it looks like it might be a problem changing preset on the fly to control all the outputs (approx 8 of them). Anyone have any experience with this application? Maybe I am forced to use 1769-HSCE ? Thanks

[Guest Snerkel]

You could use a Grey Encoder, this would require 8 or 9 digital inputs (depending on resolution), beauty of this would be that the position is absolute and is remembered even when power is cycled.

[Sergei Troizky 26]

If single phase counter is OK for you, use interrupt assigned to the encoder pulse. Organize a software high-speed counter in this interrupt, and control as many bits as necessary. Refresh them immediately, if they are PLC outputs. Use >= OSR (not just =) in comparisons. In this case lost interrupt will not result in bit control failure- next interrupt will proceed it. It is little more difficult, though still possible, to organize a quadrature high-speed counter.