I have the same problem!
I am using s7-1200 TIA V13 SP!

MB_COMM_LOAD 2.1 version

MB_MASTER 2.1 Version

I used CB 1241 for RS 485 communication with Conzerve EM 6400 Meter.

I am able to run MB_COMM_LOAD, giving REQ to MB_MASTER  i am getting BUSY signal!

In my meter it was showing communication error as 'o' means, o – Parity, framing or overrun error

As i know i programmed everything correct.

Please help me to solve this issue
tell me where i could be wrong.

I am attaching my file also, please look through it.

------------------------------------------------------------------------------------------
Split from Cannot open port on CB-1241.

Hello Chaya,

I think that BUSY signal isn't enough, you need detect DONE signal with TRUE, but pls make condition to check that carefuly. Then you can continue investigate. Look pls for same communication settings between PLC and Device, this is basic. On CB board check that settings.

Update: also pls check Error and Status value, for that look at Help, there is STAUS Value legend.

Setting the receive message on the CB-1241 is a bit picky in some situations.  Be sure you think about your protocol usage and how the timing of messages works out for your baud rate, plus what may define your end of message character if one exists. This extra work can speed up communications and reduce resends.

Chaya Naga Sumanth

I have the same problem!
I am using s7-1200 TIA V13 SP!

MB_COMM_LOAD 2.1 version

MB_MASTER 2.1 Version

I used CB 1241 for RS 485 communication with Conzerve EM 6400 Meter.

I am able to run MB_COMM_LOAD, giving REQ to MB_MASTER  i am getting BUSY signal!

In my meter it was showing communication error as 'o' means, o – Parity, framing or overrun error

As i know i programmed everything correct.

Please help me to solve this issue
tell me where i could be wrong.

I am attaching my file also, please look through it.

Duris_I

Hello Chaya,

I think that BUSY signal isn't enough, you need detect DONE signal with TRUE, but pls make condition to check that carefuly. Then you can continue investigate. Look pls for same communication settings between PLC and Device, this is basic. On CB board check that settings.

Update: also pls check Error and Status value, for that look at Help, there is STAUS Value legend.

Hello DURIS_I

Thanks for the reply.

I have seen communication settings between PLC and SLAVE device, I’m pretty sure that I have programmed this part correctly.

Once I activate REQ of MB_MASTER, TxD on CB is blinking for BLOCKED_PROC_TIMEOUT at the rate of 1 sec.

There was NO ERROR and STATUS values displayed.

With regards,

CHAYA

Hello Chaya,

I will be start from this your post:

In my meter it was showing communication error as 'o' means, o – Parity, framing or overrun error

Again pls, can you confirm about same communication settings (baud rate, parity, ...) for both devices? Simply post here what communication settings are configured on Meter, pls also post Picture of your MB_LOAD and MB_MASTER instructions. What exactly registers you need touch? How you prepared DB block for recieve, what structure has? Probably ok is that if you request from MB_MASTER, light TX will show, but - common problems are incorrect communication settings or bad destination data/register number. Pls post that infos.

Update: look pls at this link, there's example that can help you:

https://support.industry.siemens.com/cs/document/109476801/controlling-a-fan-(ebm-papst)-via-modbus-rtu-using-the-simatic-s7-1200?dti=0&lc=en-WW

Hello uggy_d1

Thanks for the response.

Can you tell me what are the normal receive message setting used for CB 1241 in STEP7-1200 CPU 1241C RS485 communication

With Regards

CHAYA

huggy_d1

Setting the receive message on the CB-1241 is a bit picky in some situations.  Be sure you think about your protocol usage and how the timing of messages works out for your baud rate, plus what may define your end of message character if one exists. This extra work can speed up communications and reduce resends.

Chaya Naga Sumanth

I have the same problem!
I am using s7-1200 TIA V13 SP!

MB_COMM_LOAD 2.1 version

MB_MASTER 2.1 Version

I used CB 1241 for RS 485 communication with Conzerve EM 6400 Meter.

I am able to run MB_COMM_LOAD, giving REQ to MB_MASTER  i am getting BUSY signal!

In my meter it was showing communication error as 'o' means, o – Parity, framing or overrun error

As i know i programmed everything correct.

Please help me to solve this issue
tell me where i could be wrong.

I am attaching my file also, please look through it.

 

Hello Duris_I

Please see the attachments.

1.00-means address of the meter(slave)

O – means error

9600- baud rate

Eve – Even parity

1 – stop bits

Can you elaborate you sentence “How you prepare DB block for receive, what structure has?”
I don’t understand what you are asking.

With regards,
CHAYA 

Duris_I

Hello Chaya,

I will be start from this your post:

In my meter it was showing communication error as 'o' means, o – Parity, framing or overrun error

Again pls, can you confirm about same communication settings (baud rate, parity, ...) for both devices? Simply post here what communication settings are configured on Meter, pls also post Picture of your MB_LOAD and MB_MASTER instructions. What exactly registers you need touch? How you prepared DB block for recieve, what structure has? Probably ok is that if you request from MB_MASTER, light TX will show, but - common problems are incorrect communication settings or bad destination data/register number. Pls post that infos.

Update: look pls at this link, there's example that can help you:

https://support.industry.siemens.com/cs/document/109476801/controlling-a-fan-(ebm-papst)-via-modbus-rtu-using-the-simatic-s7-1200?dti=0&lc=en-WW

Hello Chaya,

Kaulquappe thought about crossing that 2 communication wires, simply you can have also this bad connection.

yes i tried that too!

Still i am not getting!

please how to use 

1) Response TIme

2) Wait Time

3) Transmitted message configuration

4) Received message configuration ( Message Start, Message End)

I tried with some values, but no use at all!