When separating a two-way device, which of the following is necessary?

When separating a two-way device, disarming the device is necessary because it ensures that the equipment is safely disengaged. Disarming prevents any unintended operations or activations that could occur during the separation process. This step is critical for maintaining safety protocols and ensuring that no power or signals are being transmitted through the device, which could lead to accidents or equipment malfunctions.

The other steps, while potentially important in certain contexts, do not directly relate to the fundamental requirement of safely separating the device. Ensuring a clear path of separation helps with physical safety but does not address the need to neutralize the device's function first. Notifying the railway operations center may be part of overall operational procedures, but it is not a primary concern during the immediate task of separation. Performing a system reboot is not relevant at this stage, as the focus is specifically on ensuring that the device is disarmed to prevent any unintended consequences.