read_holding_registers give exception after few hours.

[mohitbansal111]

Hi ,

I am trying to run my application to read register values from a PLC.
It's loop after 10-20 sec to read registers values and send back to server. This work successfully for couple of hour but after that it's give me exception error 'exceptions.IndexError' : 'list index out of range'.
The code snippet is following:

self.client = ModbusClient(method='ascii', port='/dev/ttyUSB0', stopbits=1, bytesize=8, parity='N',baudrate=38400, timeout=0.3)
self.client.connect()
try:
rr = self.client.read_holding_registers(list[0], list[1] - list[0] + 1, unit=0x01) #list contain continuous range of registers
if isinstance(rr, ReadHoldingRegistersResponse): 
        reg_val = rr.registers
    else
         reg_val = ''
except Exception, inst:
    print 'exception type:',type(inst)
    print 'exception:', inst
    reg_val = ''

Is my code have some problem or there is some issue in pymodbus code.

[dhoomakethu]

Could you please attach the traceback? And complete code, looks like the list you are using is the cause of the problem .
BTW, please avoid using the builtin names for your variables (in this case list)

[dhoomakethu]

should be fixed with pymodbu 1.3.1 , please reopen in case the issue still persists