FUNCTION SELECTION VIA LINE (FSL) COMMANDSFSL escape characterThe coax interface for the Xerox MRP Family is managed byspecial escape sequences sent to the printer using the FSLcommands. FSL escape sequences are command sequencespreceded by a user-defined escape character. When an FSLescape character appears in the data stream, the printer interpretsthe characters following it as a command string and not ascharacters to be printed.When you have defined an escape character, you can configurethe interface according to your needs.When a character has been defined as an escape character, youcannot use it as a normal character and print it. However, youdo not need to have an escape character defined permanently.When it has served its purpose, it can be removed.The escape character described in this chapter is different fromthe printer escape character and the IBM escape character andcannot be used for sending native printer commands or systemcommands.This section describes how to configure and manage the coaxinterface controller for the 4220/MRP and 4230/MRP by the useof escape sequences.The factory defaults of the printer suffice for most uses, and inmost cases, system software controls the facilities described inthis chapter.Types of FSL escape characterFSL escape characters are either temporary or permanent. Theirfunctionalities are as follows:Temporary (&&??n) • Changes the interface set-up.• Activates any FSL function.• Sends transparent data.• Stores and retrieves interface settings.The syntax, &&??@, for instance, defines @ as the temporaryescape character. The five-character syntax is sent to the printerfrom the host system. This escape character is not definedpermanently, and is lost when the printer is powered off.Permanent • Has the same functionalities as a temporary escape character.• Remains active at power on.Use FSL function Y48 to select a permanent escape character thatimmediately saves the settings in the permanent memory. Referto the “Y48—Permanent Escape” section for further description.Using FSL escape characterYou may define this character by sending the following charactersequence from the host:&&??@XEROX MRP FAMILY COAX COMMAND REFERENCE 3-3
