US 4,308,579 A · Multiprocessor parcel postage metering system having serial data bus

Abstract

A multiprocessor parcel postage metering system includes a system processor to which a scale subsystem processor, a postage printing subsystem processor and a peripherals subsystem processor may be connected. The processors share a common data bus over which data is transferred serially. The system processor accepts weight and status data transmitted from the scale subsystem processor over the serial data bus. The system processor operates on this data and keyboard entry data to calculate required postage as a function of parcel origin, parcel destination, class of service and selected special fees. Printer setting data is transferred to the postage printing subsystem processor over the serial data bus. Peripheral devices, such as a document printer or a parcel identification number counter, are controlled by data sent to the peripherals subsystem processor over the serial data bus. Communications are controlled by the system processor which initiates any interprocessor data transfer by means of a control signal which is interpreted by the addressed subsystem processor as a demand for information.

Claims14

Dependent claims

For controlling the transfer of data between processors in a multiprocessor system, a bus control system including:

a system processor operating under the control of a stored program to initiate any data transfer by addressing another processor in the system for a data exchange;
a serial data bus common to all of the processors in the system for carrying data to be exchanged between the communicating processors;
and
attention lines connecting said system processor to each of the other processors in the system, each said attention line connecting said system processor to only one of the other processors in the system, whereby said one of the other processors is conditioned to accept data from said system processor.

1 more element

For controlling the transfer of data in a multiprocessor postage metering system including a system processor for a scale subsystem processor for providing scale weight and status data and a postage printing subsystem processor for accepting postage printer setting data and for providing printer status data, wherein each of said processors is capable of being a data transmitting processor or a data receiving processor at a given time, a data control system comprising:

attention lines connecting the system processor to the scale subsystem processor and the postage printer subsystem processor for enabling the system processor to initiate communications with a selected one of the subsystem processors by transmission of an attention signal to the selected processor;
acknowledgment lines connecting the scale subsystem processor and the postage printer subsystem processor to the system processor to enable a selected one of the subsystem processors to acknowledge receipt of an attention signal from said system processor;
ready lines connecting the scale subsystem processor, and the postage printer subsystem processor to the system processor for conditioning a selected processor to accept data transmitted from another selected processor;
a serial data bus common to all of the processors in the system for carrying data between communicating processors, said data being segregated into multi-bit words of fixed length;
and
means for verifying the correct transmission of each data word prior to the transmission of the following data word.

3 more elements

Dependencies are inferred from the claim text.

Multiprocessor parcel postage metering system having serial data bus

Life of this patent

Multiprocessor parcel postage metering system having serial data bus

Life of this patent

Abstract

Claims14