Parker OEM750, User Manual

Page: 30 / 96

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Installation • OEM750
22
The fault output has the following electrical characteristics:
• V
CE
= 70VDC
• V
CESAT
= 0.3VDC
• Collector Current = 10 mA maximum
• Dissipation = 55 mW maximum
G
EAR
S
HIFT
I
NPUT
The gear shift input is an optically isolated input. The GS+
terminal (pin 11) is connected to the anode of the OPTO lead
via a 681
Ω
current limiting resistor. The GS- terminal (pin 12)
is connected to the cathode of the OPTO lead. The OPTO
requires a minimum of 3.5 mA—
approximately 4.0 VDC —to
ensure proper system operation. This input may be differen-
tially driven.
CAUTION
Reverse voltage in excess of 6VDC may damage this device.
With no external current limiting resistor, the current is
controlled by the applied voltage. This is due to a fixed voltage
drop of 1.5VDC on the opto LED and the internal series
resistor (681
Ω
).
The gear shift function allows a user with a limited frequency
generator to achieve higher velocities while using high resolu-
tion settings. The drive multiplies each step pulse it receives
by a factor of 8. This function may be invoked
on-the-fly ;
however, to prevent stalling and to keep track of motor posi-
tion, it should only be invoked when the motor is not moving.
Using the gear shift function is equivalent to changing drive
resolution, and may have an adverse effect on low speed
performance (smoothness). We recommend that you do not
use the gear shift with resolution settings less than 10,000
steps per revolution.