Rockwell-automation 900 Temperature Controller Communications Function Manuel d'utilisateur télécharger pdf (Page 66)

Publication 900-UM004D-EN-E - July 2010

4-8 Modbus Communications Procedure

Example: D’105.0 → H’0000041A

The variables are 4- or 8-digit hexadecimal values. Negative values are

expressed in 2’s complement format. The values are hexadecimal values with

no decimal point indication.

For example, if the 900-TC8 , 900-TC16, or 900-TC32’s process value is read

in 4-byte mode when the process value is 105.0, the read value will be

H'0000041A (105.0 → 1050 → H'0000041A).

Detailed Description of the

Services

Read Variable Area

To read from the variable area, set the required data in the command frame, as

shown in Figure 4.7.

Figure 4.7 Command Frame

CRC-16

H'03

Number of

Elements

2 bytes

Slave

address

Function

code

Read

start address

1 2 ... 61 62 63 64 65 66 67 68 69 70 71 ... 102 103

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Rockwell-automation 900 Temperature Controller Communications Function Manuel d'utilisateur Page 66