Cause
Display unit and PC can be connected without a hub when using a straight cable. Cross cables might not be usable when employing the one-to-one connection, depending on personal computers or network cards.
Solution
Provide a hub between the display unit and a PC when using a straight cable.
Make sure that the display unit and PC are connected with a straight cable via hub not with a cross cable in order to avoid incompatibility between the display unit and PC.
Distinguishing between a straight cable and cross cable
When the color-coded signal cables are arranged in the same orders from the left in the connectors, it is a straight cable. When they are arranged differently, it is a cross cable. The color-coded of the signal cables depend on the cable is used.
Straight cable
The color-coded signal cables are arranged in the same order, starting from the left White-Yellow-White-Blue-White-Green-White, White-Yellow-White-Blue-White-Green-White.
Cross cable
The color-coded signal cables are not arranged in the same order, starting from the left Black-Orange-Blue-White-Green-Black, Black-Green-White-Blue-Orange-Black.