High power digital outputs – Galil DMC-2X00 User Manual

Page 234

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Sinking

Sourcing

+5V

PNP
output

GND

I/OC

n

I/OC

n

I/O

n

I/O

n

Current

NPN
output

Current

Figure A-10

Whether connected in a sinking or sourcing circuit, only two connections are needed in each case.
When the NPN output is 5 volts, then no current flows and the input reads 1. When the NPN output
goes to 0 volts, then it sinks current and the input reads 0. The PNP output works in a similar fashion,
but the voltages are reversed i.e. 5 volts on the PNP output sources current into the digital input and the
input reads 0. As before, the 5 volt is an example, the I/OC can accept between 4-28 volts DC.

Note that the current through the digital input should be kept below 3 mA in order to minimize the
power dissipated in the resistor pack. This will help prevent circuit failures. The resistor pack RPx4 is
standard 1.5k ohm which is suitable for power supply voltages up to 5.5 VDC. However, use of 24
VDC for example would require a higher resistance such as a 10k ohm resistor pack.

*The 1-4 axis models of the DMC-2x00 all work with the IOM-1964, all have identical extended I/O
features.

High Power Digital Outputs

The first two banks on the IOM-1964, banks 0 and 1, have high current output drive capability. The
IOM-1964 is shipped with banks 0 and 1 configured as outputs. Each output can drive up to 500mA of
continuous current. Configuring a bank of I/O as outputs is done by inserting the optical isolator
NEC2505 IC’s into the Ux1 and Ux2 sockets. The digital input IC’s Ux3 and Ux4 are removed. The
resistor packs RPx2 and RPx3 are inserted, and the input resistor pack RPx4 is removed.

Each bank of eight outputs shares one I/OC connection, which is connected to a DC power supply
between 4 and 28 VDC. A 10k ohm resistor pack should be used for RPx3. Here is a circuit diagram:

1/4 NEC2505

1/8 RPx3

To DMC-2x40 +5V

DMC-2x40 I/O

I/O

n

I/OC

n

VCC

IN

GND

OUT

IR6210

OUTC

n

PWROUT

n

1/8 RPx2

Figure A-11

The load is connected between the power output and output common. The I/O connection is for test
purposes, and would not normally be connected. An external power supply is connected to the I/OC
and OUTC terminals, which isolates the circuitry of the DMC-2x40 controller from the output circuit.

224

Appendices

DMC-2X00

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