M251 Modbus server fc4

[Anonymous user]

Hi, 

can be set, to make the modbus server respond to function 4 (read input register ) ?

Thanks.

[Rodrigo_Garcia]

@AmeliaFaraci : Could you help?

[LeTomas]

Hi @Anonymous user ,

If you take a look in the page 104 of the "Modicon M251 - Logic Controller - Programming Guide" :

https://download.schneider-electric.com/files?p_enDocType=User+guide&p_File_Name=EIO0000003089.02.pdf&p_Doc_Ref=EIO0000003089

If I am not wrong based on the document the FC4 is not supported for Modbus TCP Server but if the client uses FC3 you can move the %IW to %MW in the controller.

I hope this helps you.

[LeTomas]

Hi @Anonymous user ,

A workaround could be the use of the ADDM and READ_VAR function blocks, please find below the link to download the example:

https://schneider-electric.box.com/s/bfg5ow6frqlr0lhkhweokic0j25qqg2t

If you do not know how to import it in your project you can take a look in the next video:

https://schneider-electric.box.com/s/4bvegb89udef194mavkubonmoc6pb2of

Best regards,

Letomas

[Anonymous user]

Hi Le Thomas,

Thanks, I'll give it a go.

Regards,

Louis.

[Lindamartin]

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@Anonymous user wrote: MyAccountAccess Mobile App

Hi, 

can be set, to make the modbus server respond to function 4 (read input register ) ?

Thanks.

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The Modicon M251 Logic Controller implements both client and server services so that it can initiate communications to other controllers and I/O devices, and to respond to requests from other controllers, SCADA, HMIs, and other devices. Without any configuration, the embedded Ethernet port of the controller supports Modbus server. The Modbus Client/Server is included in the firmware and does not require any programming action from the user. Due to this feature, it is accessible in RUNNING, STOPPED and EMPTY states.