
40
Generic functions
Reset sources
The reset is generally activated when the encoder reaches its designated
position. However the reset can also occur by two further mechanisms:
•
An output reset occurs if the input for that axis (see Input on page 38)
has been configured for reset. To use this mode, you should set the
Reset Position option to 'off' and the corresponding axis input to Reset.
In this case, where the input is used to reset an active output, the axis
value is not set to zero, only the Output Reset is issued.
•
If you press the [
enter
] key when in normal mode, all the resetable
axes reset. To use this mode, you should set the reset position option
to OFF for this function to be active. Note that this does not happen
when the [
enter
] key is a valid key for other functional operation. When
a reset of this nature occurs, the 'Aux. Reset' message is displayed.
You can set all the Auxiliary settings in DRO setup mode.
You can set Position 1, Position 2, Position 3, Reset Position and Pulse
width for individual axes using {
set
}. You can turn off each position status
if a particular output is not required.
Aux. output example circuit
In this example the Auxiliary Connector is used to drive an external relay.
Relay:
Manufacturer : Omron Part #: MK2PNS24DC
Contact Form DPDT
Coil Voltage Rating = 24V DC, (Maximum Voltage = 26.4V, Minimum
Voltage = 19.2V)
Rated Coil Current = 56mA, Coil Resistance = 440 ohms.
The open collector transistor output from the DP900 Auxiliary Connector
allows for a maximum voltage of 30V to be switched, and it can sink up to
150mA of driving current. In this example, both the voltage of 24V DC and
the current of 55mA, are within the specified limits (Max Voltage 30V DC,
max current 150mA).
The current that is required to activate the relay coil is approximately
55mA (calculated by dividing the External Power Supply voltage of 24V by
the Relay Coil Resistance that is 440 ohms).
The circuit diagram is shown on page 41. You need to supply the External
Power Supply. A reverse biased diode connected across the coil is used
to prevent damage to the Auxiliary Port from back EMF generated by the
Relay Coil when the Coil is switched off.