Communication using CP341 as Modbus master with 4 slaves

A

Thread Starter

Ajith

Dear Sir,

While communicating with slaves using Modbus master I am getting the following errors.

1) Event 1 of 9: Event ID 16# F1C8:0E43
IF 1: Slave Address 0 (= Broadcast) not permitted with this function code.
Incoming event

2) Event 5 of 9: Event ID 16# F1C8:0830
IF 1: Receive Error
Incoming event

Could you please send me the code (Logic) for Modbus Master is
communicationg with 4 slaves Using Siemens CP341.

Thanks,
Ajith
 
Y

Yan Samuel Ferreira Junqueira

I have the same error(0830). This error occur because the drive dont fecht data. You have configure the slaves.

Look the baud rate and the number of port.

For more question my email is
[email protected]
 
Hello Ajith;

I have done projects like yours and I can give these recommendations:
In first stage, connect the master to only one slave at a time. Phisical connections on the cable are crucial, they must be checked slave by slave, also the slave must be configured properly, and you must check the DONE and NDR bits of the Send and RCV functions to make sure they acknowledge transmissions.

Remember that if you are using a single cable to connect master and all slaves then they must all have the same interface parameters (speed, parity, stop bits...).

Once all 4 slaves work individually and you are sure they are all compatible, you must build a calling function in the master that will synchronize the pairs of SEND/RCV functions for each slave; that is, wait for the NDR bit of the RCV function for slave no. 1 before calling the SEND function for slave no.2... Do it cyclically (slave no.4, slave no.1, slave no.2...) so the processor has confirmation of each transmission before going on to the next. This slows the exchanges a bit but they are then all reliable.

Hope this helps,
Daniel Chartier
 
I am working with the manual "CP 341 Point-to-Point Communication Installation and Parameter Assignment" but this doesn't explain how I configure communication with both a CP341 and a slave (GE F650). You said that the Physical
connections are crucial, and now I don't know if my cable is ok.

Now I have the message F1CO:0E54 AND F1CO:0E52.

If you have a good manula that explains the physical connections I will be very happy. Thanks!

My email is yan @ ihm. com. br
 
Dear Mr.Daniel Chartier,
I am looking for a successful Modbus Master program for CP341 to read slaves with many Function codes.

The example program shown in CP341 manual is for single read.

I read your other post and did calling 15 nos. of FB8 and FB7 using a counter/timer to read into 15 different locations or address. but no luck.

I am successfull with only one FB8/FB7

Can you please upload your successful Modbus master program.

Thanks
 
W

Waqqas Ahmad

I have also the sma error but it the CP341 does not receive any data. I think there is some problrm with the driver MODBUS Master to be loaded in CP341. Can anyone send me the successful program.....
 
Dear Daniel

> I have also the sma error but it the CP341 does not receive any data. <

I have same problem. connceting two individual device even with one common cable is ok but I do not know how could I access their register in one program. Do you have any sample program for it?

Thank in you in advance for ypur help.

simco_110 [at] yahoo [dot] com
Best regards
Eaman
 
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