#!/usr/bin/env python
from pymodbus.client.sync import ModbusSerialClient
import time

import logging
logging.basicConfig()
log = logging.getLogger()
log.setLevel(logging.DEBUG)

client = ModbusSerialClient(method='rtu', port='/dev/serial/by-id/usb-FTDI_TTL232R_FTF48YOZ-if00-port0', timeout=0.02, baudrate=115200)
client.connect()
time.sleep(1)
log.debug("Read input registers")
start = time.time()
found = 0
for n in range(256):
    rr = client.read_input_registers(1, 1, unit=n)
    found += not rr.isError()
    print(rr)
    print(time.time() - start, found)
client.close()