Hi

I have 2 S7 1200 CPUs (1214C DC \ DC \ RLY ) 

CPU-1 ( Master) wants to only recieve data

CPU-2 (Slave) wants to only send data to Master 

I have only one RS 485 module?

Is it possible to to realize this setup?

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Split from S7-1200 TCP communication - Sample program.

Hi I checked the same project with V13 simulator .

It should communicate without any module.

I asked above questions as in the sample program there were communication modules..

I have very less time to go through manual and all

Please correct me if I am wrong so that I can complete the task soon

Hello,

why you not connect them via Profinet ports? Is your RS-485 card not used and you want use it for this situation? Give more infos.

My only requirement is to get 1 PLC reading data from the other.

Yes I have 1 RS 485 CM used for other devices. Theres no need of any CM for S7 communication

Hello,

so maybe this link can help you find solution, look for topics PUT/GET:

https://support.industry.siemens.com/cs/search?search=s7-1200%20put%20get%20example&type=ProductSupport%2CCertificate%2CCharacteristic%2CDownload%2CDownloadSoftwareArchive%2CExampleOfUse%2CFaq%2CManual%2CProductNote%2CSlk%2CForum&lc=en-WW

hi, 

to be more clear:

Why do you want to make a RS485-connection?

S7-1200 has an integrated PROFINET-interface. There is no need for RS485.

Just put an Network-Cable between them and use the I-Device-functionality.

SIMATIC S7 S7-1200 Programmable controller chapter 11.2.13

hope this helps,

regards,

Hi

its better to use TsendC and TrcvC as u can exchange M data also .

But here i am facing Delay problem 

If I want some bits form other CPU changing their states in Seconds, because of delay it changes in 2 to 3 secs in runtime. 

I didnot check with PUT/ GET instructions

Hi.

GaJEnDrA D S

Hi

I have 2 S7 1200 CPUs (1214C DC \ DC \ RLY )

CPU-1 ( Master) wants to only recieve data

CPU-2 (Slave) wants to only send data to Master

I have only one RS 485 module?

Is it possible to to realize this setup? 

Do I understand correctly?.. you have 2 PLCs that need to link with each other because you have only 1 RS485 module and the 2 PLCs both need the information from the RS485 link.

The built-in Profinet Ethernet port offers many connections for use to link PLCs with each other. Recently I had the following to this theme..

William_B

_{.....
To that end... some general information:
A1)CPU-CPU Communication with SIMATIC Controllers}

_{A2)With which devices can the S7-1200 communicate via the integrated PROFINET interface and which protocols does the S7-1200 support?}

_{More specific:   (not complete list)
B1)Sample program: S7 communication GET and PUT instructions
(Other similar topics and FAQs exists)}

_{B2)Master-Slave Communication via UDP Broadcast}

_{B3)How do you program and parameterize Modbus TCP communication between two S7-1200 CPUs?}

_{B4)Data synchronization over open communication between multiple field devices (S7-1200) and a head PLC (S7-1200/ S7-300/ WinAC).}

_.....

From your most recent response -
May we assume you have established a link between the PLCs?

GaJEnDrA D S

Hi

its better to use TsendC and TrcvC as u can exchange M data also .

But here i am facing Delay problem

If I want some bits form other CPU changing their states in Seconds, because of delay it changes in 2 to 3 mins in runtime.

I didnot check with PUT/ GET instructions

I prefer S7-communications (PUT/GET) for it is easy to use.

I suggest to exchange data between DBs It is best if the data is in one block and in byte sized increments. For example if you have 3 bits to send... better to send full 8 bits and have the other 5 bits for future expansion.

You have control over how regularly the data is exchanged -
no need to wait for full seconds to go by.

If you share some coding with us and explain what the difficulties is, then we might be able to help more. Photos of hand sketches are very welcome.. pictures speak better to ideas than text can.

Greetings
  William