The 6ES7194-2LH20-1AC0 is a 2-meter unshielded 24 V DC power cable for SIMATIC ET 200AL. One end is terminated with an M8 straight socket (4-pole, female); the other end is open wire leads for field termination to a user-supplied 24 V DC power supply or terminal block. The gray PVC jacket identifies it as a power cable (4 Li9Y 0.50 mm2 conductors, unshielded).

When do I need the open-end power cable?

In a standard ET 200AL installation, auxiliary power is distributed through the gray power bus via plug-and-socket daisy-chain cables from module to module. The open-end cable breaks out of that chain. Use it when the first module in the power daisy-chain needs to connect to a power supply that does not have an M8 port—a standard DIN rail 24 V DC PSU with screw terminals, for example. The M8 socket plugs into the module's power input; the open leads land on the PSU terminals. The 2-meter length gives enough reach from the power supply location to the first ET 200AL module in the row.

Gray means power—do not confuse with green.

ET 200AL uses gray = unshielded 24 V DC power, green = shielded PROFINET bus. This cable is unshielded—it carries only DC voltage, no data. It must never be plugged into a green bus port. The M8 connector is physically identical between bus and power cables; jacket color is the only visual differentiator. Check the color before plugging anything in.