User's Manual

Turbo PMAC User Manual

Setting Up Feedback and Master Position Sensors 69

Setting Up for Power-On Absolute Position

Absolute Power-On Position Address and Format: Ixx10, Ixx95, MI11x

Generally, position data that comes to a Turbo PMAC system as an analog voltage is absolute in nature,

so no homing search move is required if it is used for position feedback. Turbo PMAC variables Ixx10

(Motor xx Power-On Servo Position Address) and Ixx95 (Motor xx Power-On Position Format) can be

used to establish this absolute position. The Ixx10 description in the Turbo PMAC Software Reference

Manual has a complete table of the possible address settings for the ADC registers, and also for getting

absolute position from a MACRO Station.

Ixx95 should be set to $B10000 for the signed 16-bit data from an Acc-28A; it should be set to $310000

for the unsigned 16-bit data from an Acc-28B. For 12-bit unsigned data, it should be set to $0C0000; for

12-bit signed data, it should be set to $8C0000. It should be set to $740000 to specify power-on position

from a MACRO Station; station variable MI11x should be set to $17nnnn, where “nnnn” represents the

Y-address of the ADC register (or de-multiplexed register in memory) on the MACRO Station.

Scaling the Feedback Units

If the above instructions are followed, the increment of the least significant bit (LSB) of the ADC is

considered a count by the Turbo PMAC motor functions. All subsequent position, velocity, and

acceleration units are based on this definition of a count.

Setting Up Absolute Encoders

Turbo PMAC can accept feedback data from a variety of absolute encoders through various interface

boards. The instructions for setting up the hardware and software for these interfaces is detailed in the

manuals for the particular interface boards. The following table briefly summarizes these setups:

Encoder Interface Board Conversion Table Absolute Power On*

Parallel Format Acc-14D

Acc-14V

Acc-14E

Filtered Parallel ($3)

Filtered Parallel Byte ($F/$3)

Ixx95=$nn0000

Ixx95=$nn000b

Yaskawa Sigma I Acc-8D Opt 9 1/T Encoder ($0) Ixx95=$710000

SSI Acc-53E Filtered Parallel ($3) Ixx95=$nn0000

Hiperface Acc-51x Opt 2 Hi-Res Interpolator ($F/$0) Ixx95=$nn0000

Heidenhain EnDat Acc-51x Opt 3 Hi-Res Interpolator ($F/$0) Ixx95=$nn0000

Mitsubishi Acc-57E Opt M Filtered Parallel ($3) Ixx95=$nn0000

Sanyo Acc-49P Filtered Parallel ($3) Ixx95=$nn0000

Tamagawa Acc-70P Filtered Parallel ($3) Ixx95=$nn0000

*The nn in $nn0000 expresses the number of bits to use as a hexadecimal value. The b specifies which

byte of the 24-bit word to use: 4 for low, 5 for middle, 6 for high.

Details on the actual hardware and software setup for these data formats can be found in the user manual

for the appropriate accessory.