CP1L-EL/EM: Fn06 Write Register(Modbus/TCP) Function Block

Modified on Thu, 9 Oct, 2025 at 3:47 PM

Introduction

This article provides details for the use and application of the Fn06 Write Register (Modbus/TCP) function block. Using this function block with the CP1L-E provides an easy means to write a value to a Modbus register.

This function block can be of particular use in PLC-based motion control applications often found in packaging machinery. To see a machine case study of a packaging application that uses Modbus and PLC-based motion control, visit the link below.

industrial.omron.eu/converging_solutions

Fn06 Write Register (Modbus / TCP)

Name	Fn06_WriteRegister: Fn06 Write Register (Modbus / TCP)

Basic Function	Request for Write One Register
Symbol
Originates from	Tsunagi Lab Europe
Created by	OEE-HQ HvB (creation and testing)
File Name	Fn06_WriteRegister.cxf
Applicable models	CPU Unit	CP1L-EL or CP1L-EM
	CX-Programmer	Version 9.40 or higher
Conditions for usage	The following specifications can be used for FB Auto Allocation: - CIO 0000 to 6143 - HR H000 to H511 - AR A448 to A959 - D00000 to D09999 for the CP1L-EL - D00000 to D32767 for the CP1L-EM
Function Description	Fn06_WriteRegister Function Block writes one Register conform the variable value input.
Kind of FB definition	Connect Always ON type Connect the EN input to the Always ON Flag (P_ON) The same instance cannot be used in two or more places
FB Precautions	Omron can not be held responsible in case of malfunction
EN input condition	• Connect EN to condition for the FB to Work • Fn06 send the Request for Write the value • Socket Number 1 to 3 • Register Address • Value
Restrictions Input variables	• Socket Number 1 to 3
Output variables	• This FB requires multiple cycles to process. • The status of the Outputs bits are Reset if the Fn06 bit is OFF.
Application example	Fn06 Write Register Function Block is designed for use with the other Function Blocks. For more more details on the use of this function block see also CP1L-EL/EM Modbus TCP Client Socket Services. The Socket Number Output can be used for the Socket Number Input used by : - Open_Socket - Fn03_ReadRegister - Fn04_ReadInputRegister - Fn05_ForceSingleCoil - Close_Socket Example:
Related manuals	CP1L-EM/EL CPU Unit Manual (W516-E1)

Variable Table

Input Variables

Name	Variable name	Data type	Range	Description
EN	EN	BOOL		1 (ON): Starts FB 0 (OFF): Does not start FB
Write Register	Fn06	BOOL		Start request for Write Register
Socket Number	SocketNo	UNIT	&1 to &3	&1 to &3
Address	Address	WORD		Register Address to write
Value	Value	WORD		Value

Output Variables

Name	Variable name	Data type	Description
ENO (may be omitted)	ENO	BOOL	1 (ON): FB operating normally 0 (OFF): FB not operating normally
Done	Done	BOOL	Done
Error	Error	BOOL	Error
Error ID	ErrorID	UNIT	Error code: TCP/UDP Error Codes Ethernet Units Construction of Networks Operation Manual (W420) 7-3 Command/Response Reference FINS Error Codes Communications Commands Reference Manual (W342) 5-1-3 Error Codes CP1L-EL/EM CPU Unit Operation Manual (W516) 12-1 Troubleshooting

Revision History

Version	Date	Contents
1.00	21-Apr-2012	Original production

Note

This manual is a reference that explains the function block functions. It does not explain the operational limitations of Units, components, or combinations of Units and components. Always read and understand the Operation Manuals for the system’s Units and other components before using them.

Attachments (2)

cxf

Fn06_WriteRegister.cxf
6.98 KB

pdf

Fn06_WriteRegister.pdf
160 KB

CP1L-EL/EM: Fn06 Write Register(Modbus/TCP) Function Block

Introduction

Fn06 Write Register (Modbus / TCP)

Name

Fn06_WriteRegister: Fn06 Write Register (Modbus / TCP)

Basic Function

Request for Write One Register

Symbol

Originates from

Tsunagi Lab Europe

Created by

OEE-HQ HvB (creation and testing)

File Name

Fn06_WriteRegister.cxf

Applicable models

CPU Unit

CP1L-EL or CP1L-EM

CX-Programmer

Version 9.40 or higher

Conditions for usage

The following specifications can be used for FB Auto Allocation: - CIO 0000 to 6143 - HR H000 to H511 - AR A448 to A959 - D00000 to D09999 for the CP1L-EL - D00000 to D32767 for the CP1L-EM

Function Description

Fn06_WriteRegister Function Block writes one Register conform the variable value input.

Kind of FB definition

Connect Always ON type Connect the EN input to the Always ON Flag (P_ON) The same instance cannot be used in two or more places

FB Precautions

Omron can not be held responsible in case of malfunction

EN input condition

• Connect EN to condition for the FB to Work • Fn06 send the Request for Write the value • Socket Number 1 to 3 • Register Address • Value

Restrictions Input variables

• Socket Number 1 to 3

Output variables

• This FB requires multiple cycles to process. • The status of the Outputs bits are Reset if the Fn06 bit is OFF.

Application example

Fn06 Write Register Function Block is designed for use with the other Function Blocks. For more more details on the use of this function block see also CP1L-EL/EM Modbus TCP Client Socket Services. The Socket Number Output can be used for the Socket Number Input used by :

Example:

Related manuals

CP1L-EM/EL CPU Unit Manual (W516-E1)

Variable Table

Input Variables

Name

Variable name

Data type

Default

Range

Description

EN

EN

BOOL

1 (ON): Starts FB 0 (OFF): Does not start FB

Write Register

Fn06

BOOL

Start request for Write Register

Socket Number

SocketNo

UNIT

&1 to &3

&1 to &3

Address

Address

WORD

Register Address to write

Value

Value

WORD

Value

Output Variables

Name

Variable name

Data type

Range

Description

ENO (may be omitted)

ENO

BOOL

1 (ON): FB operating normally 0 (OFF): FB not operating normally

Done

Done

BOOL

The following specifications can be used for FB Auto Allocation:
- CIO 0000 to 6143
- HR H000 to H511
- AR A448 to A959
- D00000 to D09999 for the CP1L-EL
- D00000 to D32767 for the CP1L-EM

Connect Always ON type
Connect the EN input to the Always ON Flag (P_ON)
The same instance cannot be used in two or more places

• Connect EN to condition for the FB to Work
• Fn06 send the Request for Write the value
• Socket Number 1 to 3
• Register Address
• Value

Restrictions
Input variables

• This FB requires multiple cycles to process.
• The status of the Outputs bits are Reset if the Fn06 bit is OFF.

Fn06 Write Register Function Block is designed for use with the other Function Blocks. For more more details on the use of this function block see also CP1L-EL/EM Modbus TCP Client Socket Services.
The Socket Number Output can be used for the Socket Number Input used by :

1 (ON): Starts FB
0 (OFF): Does not start FB

1 (ON): FB operating normally
0 (OFF): FB not operating normally

Error code:
TCP/UDP Error Codes
Ethernet Units Construction of Networks Operation Manual (W420)
7-3 Command/Response Reference FINS Error Codes Communications Commands Reference Manual (W342)
5-1-3 Error Codes CP1L-EL/EM CPU Unit Operation Manual (W516) 12-1 Troubleshooting