Modbus services

Write indirect block (16)

Function 16 = 16#10, quantity = 2

The Write indirect block function permits to write 2 parameters. These parameters can be chosen by parameters [Block write data 1] (F870) and [Block write data 2] (F871) (refer to "Configuration of the indirect blocks", page 27).

Access to the parameter

This parameter is accessible in the [COMMUNICATION MENU] COM submenu of [PROGRAMMING MENU] Programming mode.

Description

Parameters

Modbus Adjustment range address

Default Valid setting after

[Block write data 1] (F870)

2160

 

16#870

 

 

[Block write data 2] (F871)

2161

 

16#871

 

 

0[No select]: No selection

1[Command word 1]

2[Command word 2]

3[Frequency Setpoint]

4[Relay command]: Ouput data on the terminal board

5[FM command]: Analog output for communication

6[Speed Setpoint]

0

Power cycle

Request:

Slave no.

Function

Starting address

Quantity of register

Byte

First register value

-------

CRC16

 

code

 

 

 

 

 

count

 

 

 

 

 

 

 

10

18

 

00

 

02

04 (fixed)

 

 

 

 

 

 

 

70

 

 

 

 

 

 

 

 

(fixed)

(fixed)

(fixed)

 

(fixed)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 byte

1 byte

2 bytes

2 bytes

1 byte

2 bytes

2 bytes

Response:

Slave no.

Function code

Starting address

Quantity of register

CRC16

 

10

18 (fixed)

70 (fixed)

00 (fixed)

02 (fixed)

 

 

 

 

 

 

 

 

 

 

1 byte

1 byte

2 bytes

2 bytes

2 bytes

Error response:

Slave no.

Function code

Exception code

CRC16

90

 

 

 

 

 

 

 

1 byte

1 byte

1 byte

2 bytes

Refer to "Error response", page 41.

Example: Write value 60Hz in the parameter [Frequency Command] (FA01) and run forward command in Altivar 212 slave 1.

Configuration:

[Block write data 1] (F870) = 1: [Command word 1] (FA00)

[Block write data 2] (F871) = 3: [Frequency reference from serial comm.] (FA01)

The Altivar 212 accepts the request:

Request:

01

10

18 70

00 02

04

C4 00

17 70

6D AF

Response:

01

10

18 70

00 02

43 B3

The Altivar 212 rejects the request because it is busy or F870 is 0:

Request:

01

10

18 70

00 02

04

C4 00

17 70

6D AF

Response:

01

90

04

4D C3

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S1A53844 01/2011

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Image 38
Schneider Electric Altivar 212 manual Write indirect block, Command word Frequency Setpoint, Speed Setpoint