Yaskawa modbus rtu any working examples?
I'm totally new to modbus, so bear with me. I'm trying to start/stop and set frequency on a Yaskawa V1000 vfd over modbus rtu. Currently I'm using modpoll. I can read some stuff using modpoll so I know the communication is working. I just don't understand the addressing.
This is from the example, red is the Start reference (1-65536, 100 is default). I'm not sure how Yaskawa address ranges work. Would I use "-r 1"? That didn't seem to work.
modpoll -b 19200 -p none -m rtu -a 3 -r 500 -c 10 COM1
This is the snippit from the manual.
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Re: Yaskawa modbus rtu any working examples?
Have a read through this FAQ - Simply Modbus - About Modbus , especially the How is data stored in Standard Modbus answer.
I'll admit Modbus addressing made my head hurt, but it's essentially to do with what address you use to access each register, as to what you actually get.
Re: Yaskawa modbus rtu any working examples?
Thanks for the Simple Modbus link. I downloaded the demo Simply Modbus Master software. It looks like I should be able to craft the messages and test the responses using that. More reading.Originally Posted by m_c
Re: Yaskawa modbus rtu any working examples?
I have modpoll working. I ended up sniffing the rs-485 bus while setting the frequency with my other control and discovered I was attempting to write to the wrong register. I was attempting to write the frequency to 0002H instead of 0280H. Doh!
Sniffed write:
01 10 02 80 00 01 02 2E E0 86 78
Decoded:
01 = ID
10 = Write command
02 80 = d1-01 (0280) Frequency Reference 1
00 01 = 1 Register
02 = 2 data bytes
2E E0 = 12000 (Set RPM)
86 78 = CRC
So now it's easy to use modpoll. I did also have to use PDU addressing addressing (-0).
modpoll.exe -p none -1 -0 -r 640 -b 9600 com3 12000
Yeah, I can now set the spindle speed.
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