Programmable controller including intelligent module

A programmable controller comprising:

• an input/output module;
• a Central Processing Unit (CPU) module;
• and
• an intelligent module,
• wherein said intelligent module is detachable from said programmable controller, is operable asynchronously with said CPU module and is operable independent of said CPU module,
• wherein said intelligent module has a structure to include a processing unit, a processing memory, an input/output interface, a module status register and a module common register,
• wherein said CPU module includes a user memory and a processing unit, said processing unit having a function of determining whether an instruction in an inputted user program should be processed by said CPU module or said intelligent module, and
• wherein when said CPU module judges that said inputted user program includes an instruction which should be processed by said intelligent module while said intelligent module is connected to said programmable controller, said CPU module transfers a part of said inputted user program corresponding to said instruction to said intelligent module which processes said part of said inputted user program in said processing unit of said intelligent module, and
• wherein when said CPU module judges that said inputted user program includes an instruction which should be processed at said intelligent module while said intelligent module is not connected to said programmable controller, said CPU module processes part of said inputted user program corresponding to said instruction.