Rockwell-automation 900 Temperature Controller Communications Function Manuel d'utilisateur télécharger pdf (Page 64)

Publication 900-UM004D-EN-E - July 2010

4-6 Modbus Communications Procedure

Variable Area

The variable area is the region of memory used to exchange data with the

900-TC8, 900-TC16, or 900-TC32 through communications.

Operations such as reading the process value and Reading/Writing parameters

are performed on the variable area.

On the other hand, operation commands do not use the variable area.

Figure 4.5

When accessing the variable area, the position of a variable in the variable area

is specified with a word identifier, area number, and address in the area.

Addresses

An address is appended to each of the variable types. Express addresses in

2-byte hexadecimal and append them for the specified access size. Each

address is composed of a word identifier, area number, and address in the area.

Figure 4.6

900-TC8 or 900-TC16

Microcomputer

Variable area

Read/write

Operation

commands, etc.

• Four-byte Mode

• Two-byte Mode

Address (2 bytes)

Area number (00 to 13)

Address in area (00 to FE): 128 variables

Word identifier (0 to 3)

Address (2 bytes)

Area number (20 to 33)

Address in area (00 to 7F): 128 variables

Word identifier (0 to 3)

0* ****A6 A0

A2A3

A5 0

A2A3

*****

1 2 ... 59 60 61 62 63 64 65 66 67 68 69 ... 102 103

Pas de commentaire

Rockwell-automation 900 Temperature Controller Communications Function Manuel d'utilisateur Page 64