NCR 7197 Owner's Manual

Also see for 7197: Owner's manual Guide Parts Identification Manual Owner's manual Wi-fi configuration guide

Contents

NCR 7197 Owner's Manual Manual pdf 144 page image

Chapter 6: Commands 7197 Owner’s GuideFebruary 2002126Status CommandsStatus Command IntroductionThe 7197 has three methods of providing status to the application. These methods arethrough Batch Status Commands, Real Time Status Commands, and Auto Status Back. Anapplication may use one or more of these methods to understand the current status of theprinter. A brief description of each of these methods follows.Batch Status Commands – These commands are sent to the printer and stored in theprinter’s buffer. Once the printer has processed all the previous commands thesecommands are processed and the proper status is returned to the application. In the eventa condition causes the printer to go BUSY, it stops processing commands from the printerbuffer. If a Batch Status Command remained in the buffer during this busy condition, itwould not be processed. In fact, no Batch Commands are processed while the printer is inthis state.Real-Time Commands – These commands are sent to the printer and are NOT stored inthe printer’s buffer. Instead, they are acted on immediately (regardless of the printer’sBUSY status) and their response (if any) is returned to the application. This gives theapplication the ability to query the printer when it is in a busy state in order to correctwhatever fault has occurred.Auto Status Back – This mechanism allows the application developer to program theprinter to automatically respond with a four byte status when certain conditions in theprinter change.Please see the subsequent sections for a more detailed description of these statuscommands. At the end of this Status Commands section is a page entitled “RecognizingData from the Printer”. This describes how to interpret what command or setting (in thecase of Auto Status Back) triggered a response from the printer.Batch ModeFor RS-232C printers, these commands enable the printer to communicate with the hostcomputer following the selected handshaking protocol, either DTR/DSR or XON/XOFF.They are stored in the printer's data buffer as they are received, and are handled by thefirmware in the order in which they are received.When a fault occurs, the printer will go busy at the RS-232C interface and not respond toany of the Batch Mode Printer Status commands. If the fault causing the busy conditioncan be cleared, such as by loading paper, or letting the thermal print head cool down, theprinter will resume processing the data in its receive buffer.