The network of devices arranged above are usually distributed throughout the plane where designers need the "doers" to perform their function. Bus Controllers are usually somewhat centrally located towards the middle, but this isn't always the case. There needs to be one Bus Controller and there really needs to be one Remote Terminal, otherwise there is no need for the network. The maximum number of remote terminals is 30. There is no limit to the number of Bus Monitors because they do not need to be talked to directly by the Bus Controller