Abstract: Article tracking logic apparatus for monitoring plural articles passing through a modular article processing system. An article path actuator activates discrete logical paths for tracking each article within the processing modules. Each logical path includes an article position memory which updatably stores the position of an associated article within an activated path. An article tracking update means is provided within each logical path to cooperate with article position transducers and error detection logic to determine abnormal article transport conditions within an active path. Decode logic is provided within each logical path to provide the control unit for the processing system with the precise path and position therein where an error has occurred.

Abstract: A modular high speed printing system for printing alphabetic and numerical information upon individual items or documents fed individually or in series through the modules. A feeder module performs accounting functions as to the number of documents processed, provides multiple or single mode document feeding and is adjustable to accommodate different size documents. The system also includes one or more printing modules for printing machine readable repetitive data, machine readable consecutive data, repetitive alphanumeric information and consecutive numeric information. A document receiver module adjustable to different size forms is also provided. The printing modules employ common document drive systems including an adjustable document end stop to permit horizontal placement of the information on the document. Vertical positioning of the information on the document is accomplished by means of adjusting the print mechanisms.

Abstract: In a modular high speed document printing system an apparatus within each printing module for inhibiting printing on a document passing therethrough when a valid print inhibiting code is sensed on the document. The apparatus employs a document lead edge sensor for sensing the presence of a document within the printing module and a print inhibiting code sensor for scanning preselected portions of a document for a print inhibiting code. A timing means is responsively coupled to the lead edge sensor for defining a time interval corresponding to the time interval wherein a valid print inhibiting code may be found. A retriggerable counter is responsively coupled to the print inhibiting code sensor for initiating counting in a memory means upon the sensing of a possible print inhibiting code. Means are provided for determining from the outputs of the counter and the timing mechanism whether a code sensed by the print inhibiting code sensor is a valid print inhibiting code.

Abstract: In a high speed document printing system a hole mask circuit is provided to compensate for erroneous indications of the entry of additional documents into the system due to the sensing of a discontinuity or aperture within the body of a valid document. The hole mask circuit receives a document present signal from an associated sensor and employs a retriggerable timing means to inhibit the recognition of an additional document unless the sensor has previously signaled the continuous absence of a document for a preselected time interval. The circuit is capable of discriminating between a valid document having apertures of a preselected maximum size, documents having invalidly sized apertures and spacings between successive documents.