Figure 6. The I And B Coordinate System On The Logical Page; Figure 7. An Example Of The Ipds Data Stream; Processing Ipds Commands - Printronix S828 Programmer's Manual

Programmer Manual PTX‐S828

Figure 6. The I and B Coordinate System on the Logical Page

Notes:
1. The S828 IPDS Printer text character box is 180 units high by 144 units wide at 10 CPI when the XpYp
units equal 1,440 per inch. The left edge of the character box is at the specified inline position and the
bottom edge of the character box is 20 units below the specified baseline position.
2. If the bottom edge of the character box falls below the printable area on the physical medium, the
character will not print. In this situation, a baseline move (Relative Move Baseline or Absolute Move
Baseline) text command can place the character box totally within the printable area.

Processing IPDS Commands

The structured field format of IPDS allows one or more commands to be sent to the printer in a continuous
stream. Each command is self-describing; the command length, type, optional parameters, and data are all
part of each specific command. The printer processes each command in the order it is received. Every
IPDS command contains a flag byte. Setting the Acknowledgment Required bit on in this flag byte
indicates to the printer the end of a command stream sequence. The printer then sends an Acknowledge
Reply to the host. Figure 7 shows an example of an IPDS data stream:

Figure 7. An Example of the IPDS Data Stream

Chapter 4 IPDS Commands 95 260071‐001A