It looks like you set the PollRateOverride to 3000.
There is something wrong with your device's Modbus response:
12:23:08.434 Send 17,3,0,0,0,21,134,149,
12:23:08.456 RCVD 17,6,0,0,0,0,33,0,1,0,32,0,32,0,33,0,32,0,36,0,0,1,215,0,125,0,125,0,125,0,120,0,30,0,2,0,0,0,0,0,1,0,10,0,7,0,22,
The received data byte 2 should be the function code of 3, not 6. The 3rd byte is the data size, but the response packet has a 0
See this for more information:
http://www.simplymodbus.ca/FC03.htm