PURPOSE: To efficiently discriminate a reception condition in a duplex processor system by discriminating the condition of receiving bus transfer information at a bus cross controller (BXC) by referring to a system identification signal when this signal is loaded on a bus and communicated to another system by a transmission side equipment.
CONSTITUTION: A system discriminating circuit 31 discriminates the condition of receiving the bus transfer information at a BXC 30 based on the own system number due to a factory order, transmission source system identification signal and a reception destination system identification signal from a system identification signal line 4b, and the system identification signal is loaded on the bus instead of including the system identification signal in the transfer information. In the case of communication to the other system by the transmission side equipment, this signal is referred to. Therefore, the condition of receiving the bus transfer information at the BXC 30 can be discriminated, and no influence is exerted upon the range of housing device identification numbers. Thus, the receiving condition at the duplex processor system can be efficiently discriminated.
ASAI MASAO
WAKIMURA YOSHIAKI
KOMACHIYA TADAYOSHI
NIPPON TELEGRAPH & TELEPHONE