PMAC/PMAC2 V1.17C A DDENDUM J UL -2005 Method/Address Word: The first setup line of a tracking filter entry contains a ‘D’ in the first hex digit (bits 20 – 23), an ‘8’ in the second hex digit (bit 19 = 1), and the address of the source X- register in the third through sixth hex digits (bits 0 – 15). If it is desired to execute a tracking filter on the contents of a Y-register, the contents of the Y-register must first be copied to an X- register in the conversion table with a “parallel” entry ($2) higher in the table. The source addresses for tracking filter entries are almost always from the conversion table itself (X:$0720 – X:$073A).
For example, to perform a tracking filter on the result of the fourth line of the table, the first setup line of the filter entry would be $D80723. Maximum Change Word: The second setup line of a tracking filter entry contains the value “max change” that limits how much the entry can change in one servo cycle. The units of this entry are whatever the units of the input register are, typically 1/32 of a count. For example, to limit the change in one servo cycle to 64 counts with an input register in units of 1/32 count, this third line would be 64*32 = 2048. Filter Proportional Gain Word:
The third setup line of a tracking filter entry contains the filter proportional gain value K p , which sets a filter time constant T f of (2 23 / K p )-1 servo cycles. Therefore, the proportional gain value K p can be set as 2 23 /( T f +1). For example, to set a filter time constant of 7 servo cycles, the filter proportional gain word would be 8,388,608/(7+1) = 1,048,576. Reserved Setup Word : The fourth setup line of a tracking filter entry is reserved for future use. It is not presently used, and can be set to 0. Filter Integral Gain Word :
The fifth setup line of a tracking filter entry contains the filter integral gain value K i , which determines how quickly the integrated error contributes to the filter output. Each servo cycle, the amount (Ki/2 23 ) * Err(n) is added to the integrator and to the filter output. Result Word: The output value of the tracking filter is placed in the X-register of the fifth line of the conversion table entry.
An operation that uses this value should address this fifth register; for example Ix03 for position-loop feedback, or the source address for a time-base conversion-table entry (to keep position lock in time base, this filter must be executed before the time-base differentiation, not afterward). Resolver Conversion Entries ($E) [Geo PMAC only]: The $E entry converts the sine and cosine resolver feedback values processed through the Geo PMAC’s A/D converter (ADC) registers to a 14-bit resolver angle value. Method/Address Word:
The first setup line of a resolver conversion entry contains $E in the first hex digit and the Y-address of the first ADC register to be read in the low 16 bits (the third through sixth hex digits). The next ADC register is read at the next higher Y-address. If bit 19 of the line is set to 0 (making the second hex digit $0) the conversion creates a “clockwise” rotation sense. If bit 19 of the line is set to 1 (making the second hex digit $8), the conversion creates a “counter-clockwise” rotation sense. T HE TWO BASE ADC ADDRESSES PRESENTLY SUPPORTED BY THE G EO PMAC FOR RESOLVER CONVERSION ARE Y:$FF00 FOR C HANNEL 1 AND Y:$FF20 FOR C HANNEL 2.
T HEREFORE , THE POSSIBLE FIRST - SETUP - LINE VALUES ARE : V1.17C Firmware Version 21