Delta MMC120 Manuale Utente Scaricare il pdf (Pagina 95)

MMC120 Linear Motion Control Module Appendix B: Event Control

Delta Computer Systems, Inc 360/254-8688 95

Appendix B: Event Control

Introduction

The Event Control feature in the MMC120 allows you to execute a sequence of commands without intervention

from the Programmable Controller (P/C). This lets the module respond to events within one millisecond rather

than the scan rate of the P/C. It also reduces the ladder logic programming required.

Overview

Event Control consists of a series of Steps which are linked together in sequences. The Steps consist of a

command area containing the instruction to be executed and a link area which specifies the next Step number

and its trigger. There are a total of 256 Steps which can be shared by both axes.

Both axes can execute any of the sequences at any time. After the Event Control Steps are configured, the

Programmable Controller need only start a Step sequence to execute a complicated motion profile. Steps in the

sequence can respond to internal conditions - positions, speeds, and status - in one millisecond rather than at

the Programmable Controller scan time.

Steps

Each Step contains a command with its associated parameters, plus the information necessary to link to the

next Step in a sequence. The Step format is as follows:

Mode Mode Word

Accel Acceleration

Decel Deceleration

Speed Requested Speed

Command Value Requested Position or command value

Command Any valid ASCII command

Link Type Condition that triggers execution of next Step

Link Value Parameter associated with Link Type

Link Next Number of next Step in sequence

Commands

Any command which can be issued by the Programmable Controller can be used in a Step.

Link Word

The Link word, which indicates the next Step to be executed (the Link Next byte), also controls when the Step

gets executed (the Link Type byte). The Link Next and Link Type bytes are stored in the two bytes of a 16 bit

word:

Link Next Link Type

(8 bits) (8 bits)

The complete Step is stored in memory in the following format:

1 2 ... 90 91 92 93 94 95 96 97 98 99 100 ... 104 105

Nessun commento

Delta MMC120 Manuale Utente Pagina 95