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I have a question about Tracking Filter
#1
I am using the ACI option card (ACC-24E3). i'm trying to apply tracking filter but i could not apply so i'dlike make an inquiry.. How do I apply the Tracking Filter?
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#2
Most of the “feedback” ECT methods (EncTable[n].type) have a tracking filter. See the section, “Tracking-Filter Operations” of Type 1 (EncTable[n].type=1) in the "Power PMAC Users Manual" for setup details (page 194).
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#3
I use the Auto-Correcting Interpolator option card (ACC-24E3) and a sinusoidal encoder. Therefore, EncTable[n].type=7 applies. How can I improve performance using the Tracking Filter in this case?
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#4
The type 7 ECT entry has the tracking filter. It functions the same as in the type 1 entry but is only documented in the type 1 entry (see previously described manual). Note that the ACI interpolator should not need the filter as it is optimized in the ASIC:
(from previously described manual)
"The tracking-filter operations for the extended hardware arctangent interpolation method are identical to those for the single-register read. Refer to the section under Single-Register Read for details. Note that the auto-correcting interpolator circuitry performs significant filtering itself in hardware, so this software tracking filter will probably not be helpful."
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#5
I have two questions.

1. I applied the Tracking Filter to the ACI option card, but the performance did not improve (Encoder Signal period 0.25um).
I want to know if it improves performance when ACI option card applying Tracking Filter. Answer with“yes” or "no",
DO not answer "probably not be helpful"

2. I use the None ACI card(ACC-24E3) and sinusoidal encoder(Encoder Signal period 20um). I applied Tracking Filter but no performance improvement. I use EncTable[n].type=1. In this case, why does not it improve perfomance?
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#6
(08-03-2018, 12:39 AM)EunSeokYun Wrote: I have two questions.

1. I applied the Tracking Filter to the ACI option card, but the performance did not improve (Encoder Signal period 0.25um).
I want to know if it improves performance when ACI option card applying Tracking Filter. Answer with“yes” or "no",
DO not answer "probably not be helpful"

2. I use the None ACI card(ACC-24E3) and sinusoidal encoder(Encoder Signal period 20um). I applied Tracking Filter but no performance improvement. I use EncTable[n].type=1. In this case, why does not it improve perfomance?
We are using the ACI with 0.250 um scales and they work quite well over the full velocity range of the scale without any filtering. If there are no improvements by applying the tracking filter it is likely the problems lay elsewhere in your system. At this resolution direct drive systems with low noise/low distortion linear amplifiers are usually required.
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#7
(08-03-2018, 12:39 AM)EunSeokYun Wrote: I have two questions.

1. I applied the Tracking Filter to the ACI option card, but the performance did not improve (Encoder Signal period 0.25um).
I want to know if it improves performance when ACI option card applying Tracking Filter. Answer with“yes” or "no",
DO not answer "probably not be helpful"

2. I use the None ACI card(ACC-24E3) and sinusoidal encoder(Encoder Signal period 20um). I applied Tracking Filter but no performance improvement. I use EncTable[n].type=1. In this case, why does not it improve perfomance?

You should not use tracking filters when using ACI.
Sinusoidal encoders are used in very high precision applications. Any unnecessary delays such as filters will degrade performance rather than improve performance.
If your performance does not meet the requirements, please look for problems from mechanical structures, drives, and electrical systems.

If you want to use type=1 to get the position, you can refer to the ACC-24E3 manual Reading the Data as a Serial-Interface Position Value chapter. The ACC-24E3 ASCI chip will transfer the processed data to you via the serial bus.

Simulated Serial Encoder Position
To use the encoder position in the ASIC obtained from the FPGA through the serial encoder interface for ongoing servo position, the following saved setup elements must be specified:
EncTable[n].Type = 1 // Single-register read conversion
EncTable[n].pEnc = Gate3[i].Chan[j].SerialEncDataA.a // Serial register
EncTable[n].index1 = 0 // No left shift or filtering
EncTable[n].index2 = 0 // No right shift or filtering
EncTable[n].ScaleFactor = 1/16384 // For result in encoder quadrature counts
Motor[x].pEnc = EncTable[n].a // Use table result for position-loop feedback
Motor[x].pEnc2 = EncTable[n].a // Use table result for velocity-loop feedback
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