RS485 Request-Frame in Hex / Interpreter of Response-Frame in Hex

[mhalex]

Hello togehter,

I use a V1210 for my Visualisation Project of digital pressure transmitters.

They are working with RS485 BUS and their own Protocol (Meriam Serial Protocol).

In first test i tried to get the information how to Request via RS485 a new Measurement signal and in which format the transmitter is answering in a Response Frame.

 

In this Case i already know that i have to send on RS485 Bus /11920Baud 8 Data Bits 1 Stop Bit Parity: None the following Frame(hex):

80 01 00 05 0B 04 92 00 00 00 06 10 05 80 80 0B F0 40

Answer:
40 01 20 0B 05 04 92 00 00 00 7D 9D 00 02 03 00 F9 4E 4A 41 C1 5E 58 BD 1B 3B 5E 41 00 01 01 00 E9 60 B6 41 91 DE B5 41 52 07 BB 41 0B F0 40 05 80 80

In the marked 4 Byte-little Endian Code is the Pressure of my transmitter shown.

HEX: F9 4E 4A 41

Float - Little Endian (DCBA) : 12.64428 

 

How can I implement such a Request Frame and how can I manage the Answer frame for visualisation of the pressure value?

I already setted up a Protocol Config and a PROTOCOL Send - in the Protocol Send Block. But after closing and reopening the Code is missing?!

 

Looking forward hearing from you soon.

 

Kind Regards

Alexander






 

 

 

[kratmel]

In this type or application i use PC with terminal program for send message to non standard device and recieve answer.

This terminal program can be used for test - what PLC is send and device answer in result.

 

Main idea - save answer as string and operate with data convertion "offline".

Joe Touser post many tips about non standard Protocol  on forum. Please use Search.....

 

[mhalex]

Hello kratmel,

I read some posts of Joe and already did this tests with the terminal-program hterm. 

As you can see my Request-String was sended via hterm:

RS485 Bus /11920Baud 8 Data Bits 1 Stop Bit Parity: None the following Frame(hex):

80 01 00 05 0B 04 92 00 00 00 06 10 05 80 80 0B F0 40

And i got the Answer in hterm:
40 01 20 0B 05 04 92 00 00 00 7D 9D 00 02 03 00 F9 4E 4A 41 C1 5E 58 BD 1B 3B 5E 41 00 01 01 00 E9 60 B6 41 91 DE B5 41 52 07 BB 41 0B F0 40 05 80 80

In the marked 4 Byte-little Endian Code is the Pressure of my transmitter shown.

HEX: F9 4E 4A 41

Float - Little Endian (DCBA) : 12.64428 

Now I'm interested how to send such a HEX Code with the Vision and how to interpret the answer 4-bytes in the Response-String.

 

 

[kratmel]

In att. i post some sample with non standard modbus via protocol.

You can see TX - send  and RX - scan idea.

 

 

samba_protocol sample.vlp