Modbus slave link message parameters – Rockwell Automation AADvance Controller Configuration Guide User Manual

Page 231

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Document: 553633
ICSTT-RM405f-EN-P
Issue 07

9-45

Modbus Slave Link Message Parameters

Each Modbus slave link message has a set of parameters as detailed in the table.

Table 33:

Modbus Slave Link Message Parameters

Description

Value(s)

Default

Remarks

Command

Read Inputs;
Read Coils;
Write Coils;

Read Input Registers;
Read Holding Registers;
Write Holding Registers

Read Coils

Command type specifies
the direction of the
message

Slave

1 to 65,536

1

Range of values usable
depends on the slave
device

Master Mimic

Depends on command —

see table below

Various

Master

1 to 65,536

1

Count

1 to 2,000 for a Write Coils
message;

1 to 125 for a Write Holding
Registers message

Control

1 to 65,536,

or 0 to disable

The address of a control

register (coil) (†)

0 = enabled

1 = disabled

Note: (†) The 'remarks' here summarize the values allowed for the contents of the
register.

Table 34:

Master Mimic Values for Modbus Slave Link Messages

Command

Master Mimic Value(s)

Default

Remarks

Read Inputs

Coils

Coils

Read Coils

Coils

Coils

Write Coils

Coils;
Inputs

Coils

Read Input Registers Holding Registers

Holding
Registers

Read Holding
Registers

Holding Registers

Holding
Registers

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