Asynchronous Terminals and Printer Processes Programming Manual

INTRODUCTION

System Generation

is not used, each communication line is driven by a separate

process. The MULTI modifier enables a group of lines to be

driven by a single process. With ATP6100, the MULTI modifier

can cause a single process to control up to 8 LIUs (from 8

to 32 subdevices, depending on whether the LIUs are LIU1s or

LIU4s). SYSGEN automatically selects MULTI for TERMPROCESS and

SERIALPRINTPROCESS. You can also select MULTI for subdevices |

accessing TERMPROCESS or SERIALPRINTPROCESS with DSC. The |

ALLPROCESSORS paragraph describes processor attributes that are

common to all processors.

The optional PROCESSORS paragraph defines table sizes that differ

from processor to processor. This paragraph is not used when |

configuring devices controlled by a 3681 MFC. |

PROCEDURE CALLS FOR ACCESSING TERMINALS AND PRINTERS

Application programmers use GUARDIAN 90 file-system procedure

calls to interact with terminals and printers through ATP6100,

TERMPROCESS, and SERIALPRINTPROCESS. The OPEN and CLOSE calls

start and stop communication with files. READ and WRITE move

data to and from the file. CONTROLBUF, SETMODE, and SETPARAM

control device-dependent characteristics of ATP6100 subdevices

and TERMPROCESS and SERIALPRINTPROCESS devices. The commands

used to control terminals differ slightly from those used for

printers. See Sections 3 and 6 for programming examples. Refer

to the

System Procedure Calls Reference Manual

for detailed

information.

COMMUNICATIONS MANAGEMENT INTERFACE (CMI)

This subsection describes the general features of CMI as they

relate to ATP6100, TERMPROCESS, and SERIALPRINTPROCESS. Refer

to the

Communications Management Interface (CMI) Operator’s Guide

for a complete description of CMI. Refer to Sections 2 and

5 of this manual for more information about how CMI controls

asynchronous terminals and serial printers. For information on |

the CMI limitations associated with 3681 support of asynchronous |

subdevices, see Appendix F. |

CMI is an interactive interface that allows operators and network

managers to do the following tasks:

• Change the configurations of data communication subsystems

• Create traces of line activity to assist in solving problems

November 1987 1-11