beautypg.com

Schneider Electric Processor Adapter User Manual

Page 410

background image

Ladder Logic Elements and Instructions

410

870 USE 101 10 V.2

DX Loadable Support

Introduction

The M1 CPUs can use DX loadable instructions, which support optional software
products that can be purchased for special applications. DX loadables provide the
user with special ladder logic functions.

Loaded on
Page 0

The code for DX loadables gets loaded into the Page 0 area. Thus, for every word
of DX loadable that is loaded, one word of Page 0 becomes unavailable for other
use (such as application logic).

Limited
Functionality

DX loadables are limited in the functionality they can provide because they do not
provide storage for variables and are limited in their size.

M1 Support

M1 supports only loadables targeted for 80x86 microprocessors running in 16-bit
real mode that have not made any hard-coded hardware assumptions (e.g., the
address and format of the TOD clock). Obviously, there must be enough available
memory to fit the loadable.

Saved to Flash

Since DX loadables are stored in Page 0 memory, they are saved whenever a
save-to-Flash operation is initiated.