Hey Everyone,

Step 7 Version : V5.5 + SP4

TIA Portal Step 7 : V13 SP1 Udpate 9

I am having a system which consist of CPU 414-5 H PN/DP with ET 200SP as decentralize periphery.

I have  CM PtP (6ES7 137-6AA00-0BA0) installed and to be used as MODBUS MASTER (RS485 2W)

Following the given two links i proceeded with the programming, 

Required blocks were downloaded from this link: PtP communication instructions used on distributed I/O of an S7-300/400 

Documentation:  PtP instructions for use of ET 200MP / ET 200SP in the distributed peripherals of a S7-300/400 with Step 7 V5.5

Well, on doing so, I am unable to establish the connection with Slave device.

Am I missing any update package ???

Or its just the way i made the blocks ???

For instance I have set a CPU 1510SP-1 PN with CM PtP (6ES7 137-6AA00-0BA0) installed as a SLAVE. 

I am attaching S7 Program for the Master ( Only the communication part ) 

Your Kind support is highly appreciated !!!

Hello,

Have a look in attached sample code. Use  "Modview" Modbus RTU simulator testing software as Modbus RTU Slave.

DJ_1

Hello,

Have a look in attached sample code. Use  "Modview" Modbus RTU simulator testing software as Modbus RTU Slave.

 Hello,

I checked the Attachment, but the issue still exist unfortunately,

I would say whats in the attachment is almost the same with what i have attached !! 

On compiling the blocks, I get an error of a missing " UDT 612" ,,, Where do I find this UDT ??!

Does this have to do anything with my issue !! 

Regards !!

Hello,

pls attach screenshots from ET200SP RTU Master (if more, zip them and attach here) where you have configured COMM_LOAD and MASTER instructions, of course better in ONLINE mode. Check if you have same communication settings on both sides (speed, data bits,...) and correct set of Slave address in both sides also.

Duris_I

Hello,

pls attach screenshots from ET200SP RTU Master (if more, zip them and attach here) where you have configured COMM_LOAD and MASTER instructions, of course better in ONLINE mode. Check if you have same communication settings on both sides (speed, data bits,...) and correct set of Slave address in both sides also.

 Hey,

please find the attachment,

Right now am trying to set the communication with MODBUS simulator,

The thing is, At he moment the status of the FB Modbus Master shows always Buzy (7002) , without any successful done loop.

Do I miss something in the assignment of the Modbus Master block or is it the way i initialize the Modbus Comm port FB640 ??!

With Regards  

Hello,

look to your DATA LEN area definition. You requested 16#50 which is DEC 80 but in pointer you only define for 50 WORDs. This can be problem. Also pls check all parameters available in PC simulator due your request, so data are available from holding register address with next 50 words as you have requested. For test you can request only for 10 WORDs f.ex. and can leave defined receive DB for that 50 WORDs structure.

Update: don't have now this HW available but also check if you need set other type of protocol on your CP, you have now there Freeport but check if relevant Modbus must be set there!

Duris_I

Hello,

look to your DATA LEN area definition. You requested 16#50 which is DEC 80 but in pointer you only define for 50 WORDs. This can be problem. Also pls check all parameters available in PC simulator due your request, so data are available from holding register address with next 50 words as you have requested. For test you can request only for 10 WORDs f.ex. and can leave defined receive DB for that 50 WORDs structure.

Update: don't have now this HW available but also check if you need set other type of protocol on your CP, you have now there Freeport but check if relevant Modbus must be set there!

Dear Duris,

I changed the DATA LEN  to HEX instead !! And I would say am able to do write into the simulator which is as slave ,,, But when it comes to reading from the slave, The communication is not successful, I believe the error is within the Receive P2P parameters which are a part of the Instance DB of the Modbus master..

Hello,

if you're using RS-485 interface, look to instance DB and change that interface option (RS-485 2 wire) directly. I think now (hope good remember) with value 4. Sry now really don't know exactly, but this was obvious problem of users.