connect delay

[CiNcH83]

Hi @favalex

Using your tool a lot. Big thanks.

There is one little suggestion... some devices (like Huawei SUN2000) require a delay after connecting or else the following request will fail. I quickly added a little sleep after connect to fix that.

[favalex]

Hi, if you have the opportunity please give this PR #43 a try. In any case I will make a new release shortly.

[CiNcH83]

Thanks. Works beautifully:

$ modbus 192.168.1.12:502 -s 1 -v h@32108/I
Parsed 0 registers definitions from 1 files
→ < 3a 28 00 00 00 06 01 03 7d 6c 00 02 >
TimeoutError: timed out

$ modbus 192.168.1.12:502 -s 1 -d 1 -v h@32108/I
Parsed 0 registers definitions from 1 files
Sleeping 1.0 seconds after connect
→ < 3d 16 00 00 00 06 01 03 7d 6c 00 02 >
← < 3d 16 00 00 00 07 01 03 04 00 2d f3 15 > 13 bytes
← [45, 62229]
32108: 3011349 0x2df315

One thing I also keep using your tool for is to profile access response times:

    def perform_accesses(self, accesses, definitions):
        start = time.perf_counter()
    
        for access in accesses:
            if access.write:
                access.write_registers_send(self)
            else:
                access.read_registers_send(self)

        for access in accesses:
            if access.write:
                access.write_registers_receive(self)
            else:
                access.read_registers_receive(self)
                access.print_values(definitions)
        
        end = time.perf_counter()
        
        elapsed_ms = (end - start) * 1000
        
        logging.info ('Duration: %d ms', elapsed_ms)

        return self

Dunno whether you want to add something like that as well.

In any case I will make a new release shortly.

Highly appreciated as I am on master already due to the slave ID 0 fix.