Have to write values to external device register (40000---) in MODBUS TCP/IP communication

Hi sir 

 using s7- 1200 i have  to write values to external device register (40000---)  in MODBUS TCP/IP communication. currently that devices as works as a Master .. 

i want to how to write external devices register 40000.

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Split from Tips and sample program for MODBUS TCP.

Hi,

when the access theMB_Client's block help, you can navigate in the help system to the topic "MB_MODE, MB_DATA_ADDR and MD_DATA_LEN parameters", there you can get a address table.

When you use MB_server, you are restrict to the MB_Hold_reg area

Abhityasm

Hi sir 

 using s7- 1200 i have  to write values to external device register (40000---)  in MODBUS TCP/IP communication. currently that devices as works as a Master .. 

i want to how to write external devices register 40000.

------------------------------------------------------------------------------------------
Split from Tips and sample program for MODBUS TCP.

 If device is a MASTER, it means you gonna be slave, device will ask you for your holding register

(40000---). In that case you need to use MB_MASTER FB inside s71200. Take a look at picture.

But it is more likely that you are Master and Device is a slave, since you need to write something on device registers, in that case u need to use MB_CLIENT.

Hello,

if I could add next sugestions, for first I need point that address 40000 I see possibly not reachable if you not specify exactly how you mean that value. Next sugestion is that, even if you implement MB_CLIENT you can't be lucky with functionality because on partner side it needs to be implemented Server side. Simply we don't know your partner side HW, possible resources enough. Simply maybe on partner side can't be Server implemented already due some not known restrictions, this you need check with partner.