USER MANUAL Appendices 195
Output Command Result
CBn Vout = GNDiso
SBn Vout = Viso
The resistor pack RPx3 is removed to provide open collector outputs. The same calculations for
maximum source current and low level voltage applies as in the above circuit. The maximum sink
current is determined by the NEC2505, and is approximately 2mA.

Open Collector
1/4 NEC2505
To DMC-1748 +5V
DMC-1748 I/O
I/O
n
OUTC
n
1/8 RPx2

Electrical Specifications
I/O points, configurable as inputs or outputs in groups of 8

Digital Inputs

Maximum voltage: 28 VDC
Minimum input voltage: 4 VDC
Maximum input current: 3 mA

High Power Digital Outputs

Maximum external power supply voltage: 28 VDC
Minimum external power supply voltage: 4 VDC
Maximum source current, per output: 500mA
Maximum sink current: sinking circuit inoperative

Standard Digital Outputs

Maximum external power supply voltage: 28 VDC
Minimum external power supply voltage: 4 VDC
Maximum source current: limited by pull up resistor value