Owner's manual

A–B

Chapter

5–1

Using the RS-232 Ports

In this chapter we describe how to:

• Connect RS–232 device(s) to the CVIM module.

• Obtain results data using ASCII or DF1 protocols.

• Upload and download configurations.

In addition, this chapter provides example programs.

Using the RS–232 interface you can link a variety of devices to the CVIM

module:

• Computers

• Operator Interfaces such as Allen–Bradley Industrial Computers and

Terminals with serial ports.

• I/O modules such as the Basic Module (Catalog No. 1771–DB) or ASCII

module (Catalog No. 1771–DA).

• Allen-Bradley DATAMYTE and Dataliner devices (requires USER-PAK

Software, Catalog No. 5370-UPK).

All commands are simple ASCII and/or Hexadecimal strings. Refer to

Appendix E for an ASCII conversion chart. These commands can be

generated using a variety of programming languages (C, Fortran, BASIC).

This chapter provides a sample ASCII program (written in BASIC) and a

sample DF1 program (written in C).

There are two protocol options when you select an RS–232 communications

port (A or B):

• ASCII

• DF1

This chapter describes both of these options. First we describe the ASCII

protocol (page 5–5) and then the DF1 protocol (page 5–29).

Chapter Objectives

RS–232 Communications

ASCII and DF1 Protocols