Digital Parallel Interface - Metrologic M20-EPS User Manual

4.2 – Digital parallel interface
Picture 12 - DB25F rear
connector– Digital I/O
interface
Photo-couplers OC1 to OC10 integrate the output parallel interface, where 10 open-
collector are accessible to the user (common emitter connected to pin 18 and outputs
OUT1 to OUT10 connected to pins 1, 2, 3, 4, 5, 6, 14, 15, 16 and 17 respectively).
Photo couplers OC11 to OC20 integrate the input parallel interface, where 10 led
activated inputs are accessible to the user (common power pin 5~24V at pin 25 and
inputs IN1 to IN10 connected to pin 8, 9, 10, 11, 12, 13, 21, 22, 23 and 24 respectively).
Picture 13 – Digital I/O interfaces – electrical schematic diagram
In Picture 14 and Picture 15 two typical interface applications to external hardware
are detailed. Picture 14 shows a M20 output pin connected to a PLC device. Picture 15
show a M20 output pin connected to a relay for powering high loads (lamps,
electromechanical actuators or other automation devices).
30
The M20-EPS features two digital ports, each 10-bit
wide, as shown in Picture 12).
Both input and output interfaces are photo-coupled,
with high immunity to external environment and coupled
noise.
In Picture 13 an electrical diagram details each
interface and connector pins.
M20-EPS User Guide