New VFD comms timeout -12

So what I am taking away from your wonderful description is this :
Comms are happening in both directions, and are understood by each side.
MAYBE the actrual issue here is the register to say enable spindle is the incorrect register in my drive, so the response is illegal data address?

Not sure about the coil observation yet.

Is it odd that there is only 6 bytes received then a time out occurs? Could I have some type of issue with the comms and data is getting corrupt? Again I want to point out this is the same setup I had before on a different VFD and worked fine. I literally disconnected the wires from 1 and connected them to the other.

If I understand this correctly, it is trying to read the data starting at address 0305h?
If thats true, I think that address does not exist in my controller.

MAYBE the actrual issue here is the register to say enable spindle is the incorrect register in my drive, so the response is illegal data address?

Note that it says that it is 'reading setup parameters:' which fails. Enabling the spindle would not be a read function.

Is it odd that there is only 6 bytes received then a time out occurs?

The component does not handle exception responses (which are only 5 bytes), I guess.

I'm afraid I cannot help much more as I have no information about the vfd or the setup values for the component.

Could I have some type of issue with the comms and data is getting corrupt?

No, modbus uses a crc checksum (ie the last two bytes of the messages). If your request got corrupted the crc would be wrong and the vfd would then ignore the request and you would not receive any response.

btvpimill wrote:

If I understand this correctly, it is trying to read the data starting at address 0305h?
If thats true, I think that address does not exist in my controller.
 

No, the layout is:

[01] Modbus address
[01] Read Function
[03] Three byte command
[05] Read parameter 5 ( PD005 Max Operating Frequency )
[00, 00] placeholder data, unused
[2C, 4F] Checksum.

Your error response is:

[01] Modbis address
[81] Error bit (80) + the command [01] = 0x81
[02] = Illegal Data Address*
[C1, 91] Checksum

I don't know why it is saying "illegal address" as this has been working for several years on my own lathe with HyVFD and the driver code hasn't changed very much in that time. 

_My_ VFD isn't even sending a valid response, or a correct checksum. 

Function code 40 is wrong, 0xA0 is _way_ too many bytes, d0 isn't an exception code, and 36EE is not a valid checksum. 

Unfortunately I can't even see my VFD control panel without pulling the lathe away from the wall. I really hope I don't need to do that. Though it would be a good opportunity to fit a braking resistor. 






*The data address received in the query is not an allowable address for the slave. More specifically, the combination of reference number and transfer length is invalid. For a controller with 100 registers, a request with offset 96 and length 4 would succeed, a request with offset 96 and length 5 will generate exception 02.

I found the problem with my setup (I don't think it helps you)

I had to set "-p none" to indicate that there is no parity in the serial comms. The hy_vfd driver claims to default to odd parity. I think that I have a vague recollection that this didn't work, and so it was setting no parity. So I had my VFD set up no-parity to suit the broken driver.