42 IM805 Operating Instructions Revision R032306
43
IM805 Operating Instructions Revision R032306
P o w e r i n g t h e O p t o c o u p l e r s
In order to maintain isolation, the optocouplers must be powered by an
external power supply connected to P1:4, with the opto supply ground
connected to the ground of the input control circuitry. The logic inputs are
internally limited to allow for a +5VDC power supply.
A power supply in excess of +5 volts may be used, however a current
limiting resistor
MUST
be placed in series with the input to limit the input
forward current to the recommended 7 milliamps. At no time can the input
forward current exceed 15 milliamps or damage may occur to the drive.
WARNING! The isolated logic inputs on the IM805 are internally
limited to allow for an optocoupler supply voltage of +5 VDC. If
using a higher voltage supply, a current limiting resistor must
be placed in series with the input or damage will occur to the
IM805’s input circuitry, rendering the drive inoperable.
Table 7.3: Recommended Input Current Limiting Resistor Values
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I s o l a t e d L o g i c I n p u t C h a r a c t e r i s t i c s
S t e p C l o c k ( P 1 : 2 )
The step clock input is where the motion clock from your control circuit-
ry will be connected. A positive going edge on this input will increment
or decrement the sine/cosine position generator in the IM2000 ASIC. The
size of this increment or decrement will depend on the microstep resolu-
tion setting. The motor will advance one microstep in the plus or minus
direction (based upon the state of the direction input) on the rising edge
of each clock pulse.
The positive going edge of this input will also update and latch the states
of the direction and microstep select inputs. If no change has occured to
these inputs then the drive will make the next step.
