JPH0319582B

PURPOSE:To reduce the ON-OFF frequency of I/O power supply and to extend the life of power supply, by feeding and breaking the power supply for transaction processing devices having the change in the state of the power supply in response to new transactions when the designated types of the users are changed. CONSTITUTION:A plural kinds of transactions are shared at transaction processing devices, the shared processing is selected based on the operation of the users and the power supply is applied from a control means is response to the transaction of each transaction processing device. A power supply switching circuit 13 is provided between a main power supply 4 of the control means and each I/O and to secondary I/O power supplies 21-24 of the circuit 13, a power supply control circuit 11 and a storage circuit 12 are connected. The power-on instruction of a control key is inputted to a the circuit 12 to input the power supply status notice before setting from the circuit 12 to a reset terminal. In response to the new transactions, the power supply of the transaction processing devices having the changes in the state of power supply is fed and broken at the circuit 11, to reduce the I/O power supply frequency of on/off of the I/O power supply 4 effectively and to extend the life of the power supply 4.