Intelligent Motion Systems MFM Motion Detector, Руководство по эксплуатации

Страница: 60 / 74

40
Microstepping MForce PowerDrive Manual Revision R032008
PWM Control Bits
Bit 7 – QUIET
This bit changes PWM operation. When quiet is set, the bridge logic does not enter the reverse
measure period, therefore there are fewer transitions. The bridge is disabled during zero cross. This
mode is used at rest or when moving very slowly. When quiet is cleared, normal bridge operation is
selected.
Bit 6 – Not used
Bit 5 – SYNC_EN
This bit controls the synchronization of the bridge PWM with the zero cross. When the sync_en bit
is set, the bridge PWM will be synchronized with the positive front slope of the sin phase at each zero
cross.
Bit 4 – RECIR
This bit controls where the motor current will recirculate within the bridge during the recirculate
period. When recirc is set, the motor current will recirculate in the high portion of the bridge. When
recir is cleared, the motor current will recirculate in the low portion of the bridge.
Bits 3..1 – TODLY - Turn on Delay
This value sets the bridge control turn on delay to prevent shoot through if a discrete FET bridge is
in use. The range is 0 to 350 nS with 50 nS resolution. Each LSB is 50 nS. The default setting for a
bridge driver is 50 nS (0x1).
Bit 0 – ENABLE
Bridge Enable, this bit is set at the factory and is inaccessible to the user.
Example PWM Settings By Motor Specifications
The following settings are based upon IMS settings per motor specifications and should serve as a baseline
to work from with regard to the manufacturer specifications of the motor being utilized. Note that these are
example settings ONLY!
Example PW Settings
Frame
Size
Stack
Size
Phase
Current
(A
RMS
)
Phase
Resistance
(Ω)
Phase
Inductance
(mH)
MASK
<mask>
Duty
Cycle
<period>
Frequency
<sfreq>
Checksum
<chksum>
14 Single 0.75 4.30 4 102 90 170 106
17
Single 1.5 1.30 2.1 136 90 170 140
Double 1.5 2.10 5.0 136 90 170 140
Triple 1.5 2.00 3.85 136 90 170 140
23
Single 2.4 0.95 2.4 136 90 170 140
Double 2.4 1.20 4.0 136 90 170 140
Triple 2.4 1.50 5.4 136 90 170 140
MForce Default — — — 204 95 170 —
Table 2.6.9: Example PWM Settings






7 6 5 4 3 2 1 0
PWMCTL
Bit
0x0203
Read/Write
Initial Value
R/W
0
R/W
0
R/W
1
R/W
0
R/W
0
R/W
0
R/W
1
R/W
0
QUIET SYNC_EN
RECIR TODLY[2:0] ENABLE
Figure 2.6.16: PWM Control Bits