Jumpy speed reporting on MDC2230

6 years 1 week ago #29529418 by Griffin Baker
Replied by Griffin Baker on topic Jumpy speed reporting on MDC2230
Okay, the controller unit logic is fixable. The problem appears to be that with the new firmware past 10/10/13 that it stalls. You should connect the RS232 lines, pins 2,3,5 of the I/O connector. Then flash via the comport the 5/25/13 firmware. You may have to flash it 2x because it tends to throw an error the first time. Just click Program again.

Then you can upload the cpld.

If you did a factory reset, have you tried unplugging the USB and power cycling the controller? The control logic is only for the encoder so it shouldn't affect the usb connection.
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6 years 1 week ago #29529423 by jgannon
Okay, I've managed to bring the controller back to life. Do you have the DFU version of the older firmware so I can try that? That's a better option for me right now.

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6 years 1 week ago #29529424 by Griffin Baker
Replied by Griffin Baker on topic Jumpy speed reporting on MDC2230
See attached
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6 years 1 week ago #29529426 by jgannon
I've downgraded the firmware and updated the control logic, but the jitter issue persists. I've left the config on factory defaults, and now the two RPM values it's it's bouncing between are 300 and 450. Seems suspicious.

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6 years 1 week ago #29529428 by Griffin Baker
Replied by Griffin Baker on topic Jumpy speed reporting on MDC2230
Okay if you could, can you gives us the manufacturer name of the encoder you are using as well as the model number? Typically in the event the encoder CPLD is not installed, the counter 1 will climb on its' own. But in your case, it seems to be stuck at 2 value ranges which is unusual. This also appears to be regardless of firmware version; though the numbers did change to a different value.

Normally, the encoder count should be 0 and 0, though sometimes it can be at -1 or 1; which is normal.

If you set the counter to 0 in the console tab, by sending !C 1 0 do you see the count still at 0? In the open loop mode, the motor should not be moving at all and neither should the counter on the encoder.

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6 years 1 week ago - 6 years 1 week ago #29529432 by jgannon
There's nothing wrong with the counter. It starts at 0, and when the motor spins, it increases steadily. It's the reported speed, in RPM, that is bouncing between two discrete values, even though the motor speed is constant. The reason the numbers changed when I changed the firmware is because I reset to factory defaults, so it's using a different Pulses/Rev value in computing the speed. Does that make sense?

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6 years 1 week ago #29529433 by Griffin Baker
Replied by Griffin Baker on topic Jumpy speed reporting on MDC2230
Okay, yes that makes sense.

So lets' try the following.

Leave the controller in factory default, except that you want to set your encoder for feedback and set to the correct PPR.

Now in the run tab, on the bottom corner, set a channel for motor command, motor power, and speed 1.

Use the top slider in the middle of the browser and give it a command from 0 to +1000. The speed reported back by the controller should vary with the motor command and not stay stuck at a range value the whole time.

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6 years 1 week ago #29529436 by jgannon
As I've noted, the motor I'm using is not connected to the controller. Right now I'm only using the controller to monitor the rotational speed. When the motor is actually going ~35 RPM, the reported speed bounces between 29 and 43. If I speed it up, it bounces between 43 and 58 instead. The reported speed is definitely related to the true speed, but it's neither precise nor accurate... that's the problem.

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6 years 1 week ago #29529438 by Griffin Baker
Replied by Griffin Baker on topic Jumpy speed reporting on MDC2230
Perhaps maybe provide some shielding for the encoder wires from the motor wires.

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6 years 1 week ago #29529439 by jgannon
I have already scoped the encoder lines right where they connect to the controller, and there is no problem with the signal.

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