PMAC/PMAC2 V1.17C A DDENDUM J UL -2005 Bits 17 – 23 of the result contain cycle data from software extension of the result to multiple resolver cycles. If the result is then used for feedback or master data, it will be further extended in the motor algorithms. This resolver conversion is a direct, and not a tracking, conversion. As such, it is more dynamically responsive, but also more susceptible to measurement noise. If a more noise- immune result is desired, at the cost of some dynamic responsiveness (but still no steady-state tracking errors), a digital tracking filter can be implemented on this result with another conversion table entry (format $D8).
The result of that filter entry can then be used as the feedback or master data. High-Resolution Encoder Interpolation Entries ($F) [New 3-line or 5-line entry for Geo PMAC only]: The $F entry in the Geo PMAC is used to process the feedback from sinusoidal incremental encoders through the Geo PMAC’s high-resolution interpolation circuitry in one of two ways. The two methods are distinguished by bit 19 of the first setup line of the entry. If bit 19 is 0, making the second hex digit $0, it is a 3-line entry that simply produces a position result with 4096 states per line of the encoder, suitable for direct use as feedback or master data.
If bit 19 is 1, making the second hex digit $8, it is a 5-line entry that produces several data results useful for setup and diagnostics of the feedback. Note that this conversion type operates differently from the interpolation entries on other types of PMACs. High-Resolution Interpolation Position Entry ($F0xxxx) [Geo PMAC only] If bit 19 of the first setup line of a Geo PMAC interpolation entry is 0, to specify an entry that produces a usable position result, this is a three-line entry (as opposed to two lines on other PMACs).
The entry combines whole-line information from the encoder counter whose address is specified in the first line with fractional-line information from the arctangent of the A/D converters whose address is specified in the second line. Note that the direction sense of both parts must agree. On power-up/reset, PMAC checks the direction sense of the counter and matches the direction sense of the fractional information to this. However, if the direction sense of the counter is then changed with the encoder-decode I-variable, the new settings must be saved and the PMAC reset to restore proper direction mapping. Method/Address Setup Word :
The first setup line of the three-line entry contains $F in the first hex digit, $0 in the second hex digit, and the base address of the encoder channel to be read in the low 16 bits (the third through sixth hex digits). In the Geo PMAC, the first encoder channel is at address $C000 and the second encoder channel is at address $C008, so the first setup line is set to $F0C000 or $F0C008. A/D-C ONVERTER A DDRESS S ETUP W ORD : T HE SECOND LINE OF THE ENTRY CONTAINS $00 IN THE FIRST TWO HEX DIGITS AND THE ADDRESS OF THE FIRST OF THE TWO A/D CONVERTERS IN THE LOW 16 BITS ( THE LAST FOUR HEX DIGITS ). T HE SECOND A/D CONVERTER WILL BE READ AT THE NEXT HIGHER ADDRESS .
I N THE G EO PMAC, THE FIRST A/D CONVERTER FOR C HANNEL 1 IS AT ADDRESS $FF00, AND THE FIRST A/D CONVERTER FOR C HANNEL 2 IS AT ADDRESS $FF20, SO THE SECOND SETUP LINE IS SET TO $00FF00 OR $00FF20. Sine/Cosine Bias Setup Word : The third setup line in a high-resolution sinusoidal-encoder conversion entry contains bias-correction terms for the sine and cosine ADC values. The high twelve bits (the first three hex digits) contain the bias-correction term for the sine input; the low twelve bits (the last three hex digits) contain the bias-correction term for the cosine input. Each V1.17C Firmware Version 23