PMAC/PMAC2 V1.17C Addendum Presently, Channels 1 and 2 are supported, and EnDat is almost always used with interpolated sinusoidal ongoing feedback, so “z” is set to 0 or 8 for Channel 1 (regular or negated, respectively), or to 1 or 9 for Channel 2 (regular or negated, respectively). Ix81 Motor x Power-Up Phase Position Address [expanded] Range: $000000 - $FFFFFF Units: Extended PMAC Addresses Default: 0 … EnDat Data Read (Geo PMAC only): If Ix81 is set to $75wxyz on a Geo PMAC, Motor x will expect its power-on phase position from the optional EnDat interface that can be built in to the Geo PMAC.
The third and fourth hex digits (wx) specify the number of bits of EnDat absolute position to be read, as a hex value. For example, if 20 bits were to be read, these two hex digits would be set to 14. The fifth hex digit (y) specifies the shift of the data read, permitting the user to match the resolution properly with that of the ongoing position. The data is first shifted left 10 bits, then shifted right by “y” bits, so “y” should be set to (NetRightShift + 10). The object is to end up with data whose LSB is equal to one quadrature count (1/4-line) of the encoder.
Most commonly, the data comes in with the LSB equal to 1/4 of a quadrature count (1/16-line), requiring a net right shift of 2 bits, so “y” should be a hex digit of “C” (12 decimal). The sixth hex digit (z) specifies the channel number used, whether the data is negated, and whether it should be matched to ongoing digital quadrature or analog sinusoidal feedback. Bits 1 and 0 together express the channel number minus one as a value from 0 to 3 (so Channel 1 to 4). Bit 2 is set to 0 if the ongoing feedback is analog sinusoidal processed through the high-resolution conversion (format $F) in the conversion table, or to 1 if the ongoing feedback is digital quadrature.
Bit 3 is set to 0 to use the data without negation, or to 1 to negate the data before using. Negating the data reverses the direction sense; this control is used to match the direction sense of the ongoing feedback as set by I9n0. Presently, Channels 1 and 2 are supported, and EnDat is almost always used with interpolated sinusoidal ongoing feedback, so “z” is set to 0 or 8 for Channel 1 (regular or negated, respectively), or to 1 or 9 for Channel 2 (regular or negated, respectively). V1.17C Firmware Version 7