Modbus communication error

Sorry I meant set offset to 1

Hello

2100 and 2101 are correct. i tried them both, in hex value and in decimal.
I also tried different offsets 0-9. none made difference.

Its about 4am here so i'm getting hazzy...

When I said element offset I meant the radio button in classiclader's modbus configuration page - it's either 0 or 1

anyways the command send seems ok but is different from your program - if I'm reading it right:

your program 0103210000018e36 broken up is 01 03 2100 0001 8e36
meaning slave 1, function 3, address 2100H, number of bytes 1, then checksome

from classicladder:meaning slave 1, function 3, address 0834H, number of bytes 1, then checksome

oh wait - in classic ladder the '1st modbus element' must be input as a decimal 8448 - not 2100

In my test config then the message is the same as your program:That looks better...

Solved.
Thanks.

It was HEX address in VFD and one should input address in linuxnc as DEC.

now works.

Thats great!
Could you post the terminal print out of classicladder so I can see the correct returned result from the VDF - I an adding some docs to linuxcnc to help next time.
Thanks

I will tomorrow.
Just went to sleeping...

Hello

Here is some debug dump.


INFO CLASSICLADDER- Modbus I/O module received: Lgt=15 -> (Slave address-1 - Function code-3 ) A 0 0 5 0 0 0 0 0 0 0 E4 89
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 0 0 1 43 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 0 0 1 43 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 1 0 0 D3 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 1 0 0 D3 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-3 Data-21 0 0 5 8F F5
INFO CLASSICLADDER- MODBUS Length we should receive=12 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
15 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=15 -> (Slave address-1 - Function code-3 ) A 0 0 5 0 0 0 0 0 0 0 E4 89
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 0 0 1 43 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 0 0 1 43 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 1 0 0 D3 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 1 0 0 D3 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-3 Data-21 0 0 5 8F F5
INFO CLASSICLADDER- MODBUS Length we should receive=12 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
15 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=15 -> (Slave address-1 - Function code-3 ) A 0 0 5 0 0 0 0 0 0 0 E4 89
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 0 0 1 43 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 0 0 1 43 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 1 0 0 D3 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 1 0 0 D3 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-3 Data-21 0 0 5 8F F5
INFO CLASSICLADDER- MODBUS Length we should receive=12 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
15 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=15 -> (Slave address-1 - Function code-3 ) A 0 0 5 0 0 0 0 0 0 0 E4 89
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 0 0 1 43 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 0 0 1 43 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 1 0 0 D3 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 1 0 0 D3 CA
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-3 Data-21 0 0 5 8F F5
INFO CLASSICLADDER- MODBUS Length we should receive=12 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
15 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=15 -> (Slave address-1 - Function code-3 ) A 0 0 5 0 0 0 0 0 0 0 E4 89
INFO CLASSICLADDER- Modbus I/O module to send: Lgt=8 <- Slave address-1 Function code-6 Data-20 0 0 1 43 CA
INFO CLASSICLADDER- MODBUS Length we should receive=5 (+3)
Serial config...
Serial writing...
Writing done!
select() for serial reading...
Serial reading...
8 chars found
INFO CLASSICLADDER- Modbus I/O module received: Lgt=8 -> (Slave address-1 - Function code-6 ) 20 0 0 1 43 CA

Thank you!