Elmo Motion Control Application Notes:Enable Signal

Enable Input

	Enable Input Specification		Enable Interface (low voltage logic)
	Enable TTL Interface (non inverting)		Enable PLC Interface (case 1)
	Enable TTL Interface (inverting)		Enable PLC Interface (case 2)

Enable Input Specification

Voltage level

Current consumption

Vin(high)

3V< Vin(high) <15V

Iin(ma) =	Vin(high) - 1.5V
	2.5

Vin(low)

Vin(low) < 1V

Enable TTL Interface (non inverting)

A pull up resistor is required because the TTL logic devices have limited output current at high level.

Enable TTL Interface (inverting)

In the inverting mode no pull up resistor is required. The TTL output current at low level is sufficient.

Enable Interface (low voltage logic)

For other types of low voltage logic no pull up resistor is required as long as:
Voutput (high) > 4 and output current is over 0.6mA (CMOS etc...)

Enable PLC Interface (case 1)

The low level voltage is defined as Vin(low) < 5V (or any other voltage that is higher than 1V). In this case the following circuit should be used:

Dz should be selected according to:

1.	Dz > Vo(low_PLC)-1V
2.	Dz > Vo(high_PLC)-5V

The higher value must be selected.

Enable PLC Interface (case 2)

The low voltage output of the PLC is.

Vo (low_PLC) < 1V

In this case a series resistor is sufficient.

Selection of Re:

Re(ma) =	Vs - 15V	(Kohm)
	0.6

If Vs is lower than 15V there is no need for Re.