Manual

Trusted

Communication Interface T8151B

Issue 21 Apr 10 PD-T8151B 32

3.5.7. Messages Tab

Figure 12 Modbus Slave Message Configuration

This panel lists all of the messages for the slave device in the order that the Modbus Master executes

them. Dragging and dropping a highlighted message anywhere in the list can be used to change the

order of the messages in the list.

To create a message to send to this slave, click ‘New’. (‘Insert’ adds a new message at the cursor

position, ‘New’ adds at the end).

Select a Message Type from the list. Depending on the address range and the number of addresses,

the appropriate Modbus command is used. The supported commands are shown below..

Address Range Size Direction Modbus Command

Low High Type Code

1 9999 1 Read Read Coil Status (Read Coils) 0x01

1 9999 1 Write Force single Coil (Write Coils) 0x05

1 9999 2 - 512 Read Read Coil Status (Read Coils) 0x01

1 9999 2 - 512 Write Force Multiple Coils (Write Coils) 0x15

10001 19999 1 - 512 Read Read Input Status (Read Inputs) 0x02

30001 39999 1- 125 Read Read Analogue Inputs (Read IP Registers) 0x04

40001 49999 1 - 125 Read Read Holding register (Read Registers) 0x03

40001 49999 1 Write Preset Single Register (Write Registers) 0x06

40001 49999 2 - 123 Write Preset Multiple Registers (Write Registers) 0x16

Table 11 Modbus Message Types

The Variable Network Address is the Modbus address range of the variables as mapped in the

Trusted

system. Only the starting address is needed; the end address is calculated automatically.

The Modbus Slave Address is the slave’s address range for the variables. Enter the start and end

addresses. The available address ranges and maximum number of addresses in a single message are

shown above.