|Signal Block Surveyor|
The Signal Block Surveyor is a tool from the Railcraft mod. This tool is used to establish signal blocks between two controller blocks, such as the Block Signal. When a Signal Block Surveyor is used on a controller, if the signal block is set up properly, it should say "Beginning Signal Block Survey" in the in-game chat. When a signal block survey is completed by using the tool on another controller, it should say "Successfully denied Signal Block" in the in-game chat. If the signal block is not valid, when the survey is attempted to be completed, it will say "Signal Block is not valid" in the in-game chat.
A proper signal block will have two controller blocks, tracks that go from one to the other that are within the controller's ranges.