Using the MDC Box to Collect Machine Signals

The MDC box has three RS-232 connectors at one end which are used to connect the RS-232 cables and explained later.

At the other end of the MDC box is a green removable spring terminal block. The green terminal block has 12 connectors, which are labelled:

1+5-50V DC or 50-110V AC Input 1
1-Common 0V Input 1
2+5-50V DC or 50-110V AC Input 2
2-Common 0V Input 2
3+5-50V DC or 50-110V AC Input 3
3-Common 0V Input 3
+24v inThis should be connected to a 24V source in the machine control
0v inThis should be connected to a 0V source in the control
+24v outThis is a fused output for Moxa W2150 / NPort 5110 / DE311 units
0v outThis is a 0V common rail for the above
+5v outThis is an isolated 5V barcode reader power supply (see note below)
0v outThis is an isolated 0V barcode reader power supply (see note below)

The MDC box is designed to be powered from the machine's 24V DC power supply - no other voltage will do. Connect the +24V terminal to the machine's 24V supply and the 0V to the machine's 0V supply. The MDC box then provides a 24V DC supply out to power a Moxa type RS-232 hub and a 5V DC supply out to power a barcode reader.

All barcode readers provided by CIMCO take power via a 1.3mm plug where the centre pin is negative (0V). Most other devices (including the Moxa hubs) have centre pin positive so it is important to get the wiring right for the barcode reader otherwise you may damage it.

If you bought your MDC box from CIMCO as a kit with an LS2208 barcode reader then the MDC box comes with the cables already connected to the green connector. Each pair of black wires has a white stripe on one wire and this is normally connected to the +VE terminal. The exception is the LS2208 barcode reader where the white stripe on the wire provided is connected to the centre pin on the power plug and therefore the other end is connected to the 0V terminal on the MDC box.

Wires can be inserted by pushing the orange release clips towards the green connector and inserting the wire fully so no copper is exposed. Release the orange clip and give the wire a pull to make sure it is secure.