초록 ▼

A programmable controller includes a processor module and a number of input/output modules housed in a rack. Each input/output module contains a circuit that identifies characteristics of the module to the processor module. The circuit has a parallel input port and a parallel output port The outputs

A programmable controller includes a processor module and a number of input/output modules housed in a rack. Each input/output module contains a circuit that identifies characteristics of the module to the processor module. The circuit has a parallel input port and a parallel output port The outputs and inputs of the two ports are interconnected in a predefined manner according to the module characteristics. In addition, inputs of the input port are coupled to either a positive or negative voltage source to identify other module characteristics. By sequentially sending data to the output port and then reading data from the input port of each input/output module, the processor can identify the characteristics of the modules in the programmable controller.

대표청구항 ▼

In a programmable controller having a processor for executing a control program, an address bus and data bus; an I/O module comprising: means for connecting said I/O module to the address and data bus; a parallel data output port having a plurality of outputs, and being addressable by said processor

In a programmable controller having a processor for executing a control program, an address bus and data bus; an I/O module comprising: means for connecting said I/O module to the address and data bus; a parallel data output port having a plurality of outputs, and being addressable by said processor through the address bus to send data through said output port which data the I/O module received from the processor through the data bus; a parallel data input port having a plurality of inputs, and being addressable by said processor through the address bus to obtain data which the I/O module receives through said input port to send data through the data bus to said processor and means for coupling at least two of the outputs of said output port to given inputs of said input port in a predefined manner which identifies the I/O module when the processor reads data from said parallel data input port.