Dear TIBI68,

I am trying to migrating your CP341 program to TIA portal V11 from step7. But i am having problems in that. FB10 was migrated easily but when i added FB10, FB7 and FB8, it was showing errors and aborted. 

I will really appreciate your kind help on this. Thank you.

Best Regards

Lohana Jack

hello all

can I use cp313c-2ptp as modbus master (because it has protocol ASCII) instade of cp 341

Hi all

I am new in modbus and need some help to make a modbus RTU master cpu 315 2DP and cp is 341-1ch02-0ae0 without dongle.

I used Dear TIBI68 program and changed libraries but TX and RX Led on cp is off.

if i disconnect the cable TX led should blink or not?

hello

I faced same your problem,status output at MBMAREQ gives error code E006h

so we need experts to help us

hello

the first comments under this topic refers to our friend TIPI68 sent some changes on library to others by email

Hi all. first of all I want to say it again, thank you Tibi68.

I'm comunicating with several slaves and everything is ok. But now, I'm trying to add a new slave to the net and I can't. It givesme status w#16#8300. someone knows what is this?

thank you.

Hi again. I know which is the problem. If I write 42001 address, FB10 comunicate 2001 and function 03. This slave needs 42001, whitout subtract 40001. Tibi68, can I open the library for look for a solution?

thank you.

Hi

Thanks for a simple and easy way to implement Modbus on Siemens. I tested this code successfully in S7-300 and now I want to use in a PCS7 system. Previously I used Modbus successfully with ET200S. Now we change the ET200S by ET200M with CP341. The problem: in the existing program the CFC library is also used, the FB's numbers are busy and we can't change (FB2: CONT_S, FB3: PULSEGEN and FB8: R_TRIG).

Is possible to make an alternative source with other FB's numbers on Siemens standard functions for easy integration on systems with CFC (for example: FB32 and FB33 for CP340; FB37 and FB38 for CP341)?

Best Regards.

Dear All,

                I have some queries about this library. I have ten  CP341 with dongle with modbus master & on each master connected with  10-12 modbus slaves.

               Is it is possible to call multiple FB-"MBMA341" for each CP in cyclic OB35 & multiple FB-"MBMAREQ" block for there respective slaves in OB1?

               Is this block use full for CP341 with RTU mode?

Thanks & Regards,

Mahesh Nakade

Dear Mahesh,

this library is totally S7 program software based and does does NOT require a dongle in the CP341.

Yes, it should be possible to do as you said. While you have a lot of CP341 you might need to increase the cycle time of the OB35 accordingly.

The protocol supported by these blocks is Modbus Master RTU only.

If you require to use Modbus ASCII protocol you need to use the dongle and official SIEMENS solution.

With 10 Master and 10-12 Slaves connected to each master don't expect high speed data update from your slaves.

If you purchased already all the hardware it's too late but there are cheaper solutions.

Best Regards.

Dear Baglietto,

I am happy to hear that you have already experience in using the library.

I received already requests from other users to change the block numbers because they are overlapping with other existing blocks in their software.

It is a very small job but it is difficult for me to adjust the numbers for everybody individually.

I am planning to post the source code so everybody can do whatever he wants with it. 

Best Regards.

Dear Chris_18,

you are right, some slaves have a bigger address area (6 digit).

These slaves cannot be addressed with this MBMAREQ version, why?

The actual MBMAREQ function block supports only 5 digit address area slaves .

I am sure that it is possible to modify the existing block but it will take time.

Best Regards.

Hello!

Mr. TIBI68, could you make special version of your library to call SFB58/59 instead of SFB52/53. A have an ancient s7-300, which doesn't support nowadays P_SEND and P_RCV functions.

Best regards,

Dmitry Konstantinov

Hi TIBI68

I have to ask for several Modbus addresses that are not ordered in the memory of the slave Equipment ,but i have a problem with this,when I try to use the function "MBMAREQ" multiple times ,the answers to the first call to the function stop coming.

This is my Code Function:

CALL "MBMAREQ" , "MBMAREQ NO.4" LINK :=MW10 RW :=FALSE SLAVE :=1 START :=L#31842 END :=L#31878 WRMODE:=FALSE S7ADDR:=P#DB26.DBX 0.0 BYTE 1 FORMAT:=0 DONE :=#Done_340 ERROR :=#Error_340 STATUS:=#Status_340 CALL "MBMAREQ" , "MBMAREQ NO.4" LINK :=MW10 RW :=FALSE SLAVE :=1 START :=L#31890 END :=L#31894 WRMODE:=FALSE S7ADDR:=P#DB26.DBX 0.0 BYTE 80 FORMAT:=0 DONE :=#Done_340 ERROR :=#Error_340 STATUS:=#Status_340 L DB26.DBW 4 T #Tension_Fase1 L DB26.DBW 8 T #Tension_Fase2 L DB26.DBW 12 T #Tension_Fase3 L DB26.DBW 16 T #Intensidad_Fase1 L DB26.DBW 20 T #Intensidad_Fase2 L DB26.DBW 24 T #Intensidad_Fase3 L DB26.DBW 28 T #Factor_Potencia1 L DB26.DBW 32 T #Factor_Potencia2 L DB26.DBW 36 T #Factor_Potencia3 L DB26.DBW 40 T #Frecuencia L DB26.DBW 44 T #Potencia_Act_F1 L DB26.DBW 48 T #Potencia_Act_F2 L DB26.DBW 52 T #Potencia_Act_F3 L DB26.DBW 56 T #Potencia_Act_Tri L DB26.DBW 60 T #Potencia_Reac_F1 L DB26.DBW 64 T #Potencia_Reac_F2 L DB26.DBW 68 T #Potencia_Reac_F3 L DB26.DBW 72 T #Potencia_Reac_Tri CALL "MBMA340" , "MBMA340 INSTANCE" LADDR :=320 WDTIME:=T#4S LINK :=MW10

Hello,

@TIBI68 Do you have TIA portal version of the CP341 Modbus RTU Master?

Hi TIBI68, 

I am really having a bad time trying to communicate a DELTA ASDA-A2 Servo drive via RS485 port, using the library that you shared to us. 

I am using a CP341 and your blocks MBMAREQ - MBMA341 with no success. I have seen in this same post, that some Users had exactly the same issue I have but I did not see the answers.

- TXD LED is flickering (every 2s) but RXD remains off.

- DONE=0,     ERROR=0      and      STATUS=16#0

Communication parameters are the same in both parts. (38400 bps, Parity NONE, 2 Stop bits, Slave Address = 1)

In the Instance DB of MBMA341, I can see that I have exactly the same data in the SEND_BUFFER[0..7] that is shown as an example in the ASDA-A2 Communications manual (Picture). However I am still getting the same result.

Also there is a NOTE in this ASDA-A2 Comms. manual saying that The power supply should provide a +12V and higher DC voltage (Picture). Is this some electrical requirement or voltage level that the CP341 does not meet.?? Because as far as I know I do not need any 12V Power supply for the Drive.

Please advice, I have to make this communication work in order to send parameters from the S7300 to the ASDA-A2 SDrive.

Thanks so much, and HAPPY NEW YEAR to EVERYONE..!!

Anthony C.

Happy New Year to you Anthony C.

while Tx is blinking properly and interface parameters match on both devices I believe that you have a wiring problem.

Swap the two wires and see if there is any change.

Best Regards.

I have swapped them a couple of times but I am still having the same effect.

My main concern is that the voltage levels for communication  on both devices (ASDA-A2 and CP341) are different because the NOTE in the Servo Drive manual I have mentioned before (The power supply should provide a +12V and higher DC voltage.), Is this possible?? I am not an expert in communication protocols (I can do good in programming though) so I would like to hear your thoughts on this. 

In CP341 User manual is stated that the port X27 (RS 422/485) interface (ASCII Driver) uses 5 Volt:  "R(A) 0V / R(B) 5V: This default corresponds to idle state (no senders active) in "Half-duplex (RS 485) two-wire mode"." 

But I have made some "research" on the web and I got confused when I found that the limits specified by the code for RS-485 protocol are -7Volts to +12 Volts. 

That is why I would like to make sure that I am not having "compatibility" problem between the two devices, since in the ASDA-A2 Software I can configure the communication protocol for the Drive as MODBUS RTU, 8 Bit, None, 2 Stop bits (Picture).

Please advice. 

Thanks in advance.