[chester88]

It's not clear to me from docs if 8n1 (8 bit data,no parity,1 stop bit ) serial signals are supported.
currently CL only supports this.
Have you connected to this inverter with modbus before?
Can you check the settings of :
H31 slave number
H34 baud rate
H35 data bits
H36 parity
H37 stop bits.

Boy are the docs written poorly for modbus!

[ninefinger]

It's not clear to me from docs if 8n1 (8 bit data,no parity,1 stop bit ) serial signals are supported.
currently CL only supports this.
Have you connected to this inverter with modbus before?
Can you check the settings of :
H31 slave number
H34 baud rate
H35 data bits
H36 parity
H37 stop bits.

Boy are the docs written poorly for modbus!

Hi Chris,

Boy, I wasn't expecting you to wade through that manual - been there done that! I did connect up briefly with my laptop and a terminal program. I sent the example of an invalid message and got the proper error response message so I left it at that. (page 12-9 of the users guide..) I do have a GE program for configuring the drive via the RS485 so I can use that to prove the communications - but its on my laptop at work (the laptop is a windows machine)

I just tried a terminal program (moserial) on the linux machine - and I get the same as before:

send: 01 03 03 31 00 14 14 4E (request 20 bytes of data)
receive: 01 83 02 C0 F1 (error response)

Here are the configuration data as it stands now -

H31 = 1 = slave 1
H34 = 1 = 9600 baud
H35 = 0 = 8 data bits
H36 = 0 = no parity
H37 = 0 = 2 stop bits

8n1 is supported I believe - I will test it now by reconfiguring the drive.

If you have your yaskawa VFD example please post it so I can have a look - it might be the piece that lets my brain put together all the pieces

Thanks for your help with this!

Mike

[ninefinger]

Chris

Turns out you can't set 8n1 - the drive automatically sets the stop bits depending on the parity - no parity is 2 stop bits, even or odd parity is 1 stop bit.

Does this mean the whole idea of using Classic Ladder is dead in the water?:drowning:

If so I'll try the other method - hacking up the gs2_vfd.c file I copied from somewhere...

Mike