The OEM750/750X does not have an enable input. You must use the remote input. The remote input is an optically isolated input that requires a minimum of 3.5mA, or approximately 4.0 VDC, to ensure proper system operation. This input may be differentially driven.
With no external current limiting resistor, the current is controlled by the applied voltage. This is due to a fixed voltage drop of 1.5 VDC on the opto LED and the internal series resistor (681 Ohm).
This input allows you to reduce current to a motor from a remote location This is accomplished by changing the current select resistor via the remote input. When the remote input is enabled, the open collector transistor internally connected to the REMOTE screw terminal will conduct to ground.
To reduce motor current to zero, short the CURRENT and REMOTE terminals together with a wire.
You can also reduce the motor current by a percentage if you short CURRENT and REMOTE with the appropriate resistor (Rremote). To calculate Rremote, first select Rc, the resistor associated with your normal operating current (see resistor selection tables in the Quick Test in the OEM750/750X User Guide). Next select Rs, the resistor in the same section of the table that is associated with your desired standby current. Then use the following equation to find Rremote.
Rremote = -13,300 (3750 + Rc) / (Rc - Rs)
Rc = Resistor associated with the operating current
Rs = Resistor associated with the desired standby current
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