Probably the topological map I already know, that is, how the middle of the specific link. For example, the central switch is connected to the layer switch with an optical fiber, and the middle is connected with the specific device. More
How many meters of cable can be customized according to the requirements.
Central locking above 4 to 5 lines, you first perform a latch, detect the lock line, the anti-theft device on the lock signal line connected to the control lock line, in the detection of unlock line, and then the remote control on the unlock signal Line in the control of the lock line can be, (you can use the probe into the line, with the test light detection)
Insulation for PVC sheathed for PVC 22 is steel tape armored