Just contact 485, I can't do equipment connected by modscan32 debugging
Because using TTL serial port, so don't consider hardware connection issue, one hundred percent are reliable

Because, in the data flow, can see the black background data, sent from the stand, completely without the code

Communication protocol that custom

By definition, is this a few byte, and the order has been in accordance with the Modbus rtu format arrayed, debug software think no data received for what?

May not be able to solve, the feeling left enough one by one, o great spirit refers to the way

CodePudding user response:

Modbus maintain registers each register is double byte, your return is a single-byte, so will not pass the check
Send:
[10] from the station address
[03] 03 function code
[00] [00] starting address
[00] [02] register number
[c7] [4] a CRC check

Receiving
[10] from the station address
[03] 03 function code
[04] returns the register number of bytes, each register 2 bytes, four bytes read two registers, so
[00] [00] register 1
[00] [00] register 2
[fb] [32] CRC check code

CodePudding user response:

Modsim32 can simulate the modbus from station, there is something wrong with the debugging can use this software simulation

CodePudding user response:

Found themselves silly questions,, a register is two bytes
Found after refer to this document, ah, halfway decent is I can't, no basic

CodePudding user response:

reference 1st floor bakw response:

keep modbus register each register is double byte, your return is a single-byte, so will not pass the check
Send:
[10] from the station address
[03] 03 function code
[00] [00] starting address
[00] [02] register number
[c7] [4] a CRC check

Receiving
[10] from the station address
[03] 03 function code
[04] returns the register number of bytes, each register 2 bytes, four bytes read two registers, so
[00] [00] register 1
[00] [00] register 2
[fb] [32] CRC check code

Yes, according to your guidance, fix the silly question, how can I get to the point and post?

CodePudding user response:

How to solve of, don't understand! Can help me with it?

CodePudding user response:

Device address is correct (to decide whether or not can be detected equipment)
The starting address is correct (device address is actually the internal storage unit, the storage unit must exist)
The CRC is properly

CodePudding user response:

The original poster can, under the guidance of the specific procedures how to write, how to change, or to set up the debugging tools

CodePudding user response:

Brother, I also met you this kind of problem, need to change from station communication protocol?

CodePudding user response:

Can I add WeChat, I encountered such a problem now, thank you.

CodePudding user response:

I can't and Modscan communications program

CodePudding user response:

I can't and Modscan communication program, which is where the master to help me to test the problem, has offered 200 yuan