Parker Hannifin
136 Aries User Guide
This command is only valid in DMODE4 (velocity mode) and DMODE6 or 7
(position mode). The LJRAT command sets the system’s load-to-rotor inertia
ratio (rotary motors) or load-to-forcer mass ratio (linear motors). The ratio is
expressed in the following equation:
• Rotary Motors— LJRAT = load inertia / motor rotor inertia
(Total system inertia = load inertia + motor rotor inertia)
• Linear Motors— LJRAT = load mass / forcer mass
(Total system mass = load mass + forcer mass)
OHALL Hall-Only Commutation
Type Drive configuration Product Rev
Syntax <a_>OHALL<i> Aries 2.10
Units i = Hall commutation type
Range 0 (sinusoidal commutation)
1 (trapezoidal commutation)
2 (DC Brushed motor commutation)
3 (Z-channel commutation – Smart Encoder only)
4 (Hall-less startup)
Default 0
Response OHALL: <*>0
See Also ALIGN, SFB, THALL
Note: This command requires a reset to take effect.
The OHALL command sets the commutation type. Use OHALL1 to set
trapezoidal commutation and OHALL2 for DC brushed motors. DC brushed
motors should be wired to motor phases U&W, if they are used. The default
is OHALL0 (sinusoidal encoder commutation once the first hall transition has
occurred).
When using OHALL 1, turn off feedback auto-detection by setting SFB to 2.
There are application limitations to observe when using OHALL4 (Hall-less
commutation startup). When the Aries drive is enabled with OHALL4 set, the
motor is moved slightly in open-loop mode and encoder position is monitored
to determine the rotor’s position in relation to the stator (or forcer/coil in
relation to the magnet track for linear motors). For this reason, OHALL4 will
not work in vertical applications or applications with heavy loads and/or high
frictional loads. If the motor has trouble turning smoothly with the drive in
“auto run” mode (DMODE1), that is a good indication that OHALL4 will be
unsuccessful.