User's Manual

Geo MACRO Drive User Manual
124 Turbo PMAC2 Related I-Variable Reference
Ixx81: Motor xx Power-On Phase Position Address and Mode
Range: $000000 - $FFFFFF
Units: Turbo PMAC or multiplexer-port addresses
Default: 0
WARNING:
An unreliable phasing reference method can lead to a runaway condition. Test the
phasing reference method carefully to make sure it works properly under all
conceivable conditions. Make sure the Ixx11 fatal following error limit is active
and as tight as possible so the motor will be killed quickly in the event of a serious
phasing search error.
Ixx81 tells Turbo PMAC what address to read for absolute power-on phase-position information for
Motor xx, if such information is present. This can be a different address from that of the ongoing phase
position information, which is specified by Ixx83, but it must have the same resolution and direction
sense. Ixx81 is set to zero if no special power-on phase position reading is desired, as is the case for an
incremental encoder.
If Ixx81 is set to zero, a power-on phasing search routine is required for synchronous fixed-field brushless
motors (permanent magnet, and switched reluctance); those that have a slip gain (Ixx78) of zero. Turbo
PMAC’s automatic phasing search routines based on Ixx73 and Ixx74 can be used, or a custom power-on
PLC routine can be written.
Note:
Ixx81 is used for PMAC’s commutation algorithms alone, to locate position within
one electrical cycle of the motor. It is not used for any servo loop position
information, even for power-up. Ixx10 and Ixx95 are used for that purpose.
Ixx91 tells how the data at the address specified by Ixx81 is to be interpreted. It also determines whether
the location specified by Ixx81 is a multiplexer (thumbwheel) port address, an address in Turbo PMAC’s
own memory and I/O space or a MACRO node number.
Note:
It is easier to specify this parameter in hexadecimal form ($ prefix). If I9 is set to 2
or 3, the value of this variable will be reported back to the host in hexadecimal
form.
Ixx81 for MACRO Absolute Position Reads using Geo MACRO Drive