New VFD comms timeout -12
- andypugh
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22 Dec 2024 01:06 #317119
by andypugh
[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.
Replied by andypugh on topic New VFD comms timeout -12
No, the layout is: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.
[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.
query_length = 6
hycomm query = [01][01][03][05][00][00][2C][4F]
query_ret = 8
response_length_computed = 8
waiting for message (8 bytes)...
read 7 bytes: 0x01 0x40 0xa0 0xd0 0x82 0x36 0xee
message was incomplete, length still to read = [01]
WAIT_DATA(): comms time outFunction 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.
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