Bug: write_single_coil() is settting all other coils to False

[beyonlo]

This bug was extracted from PR #10 report, in this reply:

I suppose that write_single_coil(), without use a list of coils, will write just on the first position, like as I asked on the #15

When I try to use write_single_coil() to write on the first position, all others coils positions are changed to False.

>>> host.read_coils(slave_addr=10, starting_addr=123, coil_qty=1)
[False, True, True, False, False, False, False, False]   <---- See that is (False, True, True..) like as on the "definitions"
>>> host.write_single_coil(slave_addr=10, output_address=123, output_value=1)
False
>>> host.read_coils(slave_addr=10, starting_addr=123, coil_qty=1)
[True, False, False, False, False, False, False, False] <---- Here all coils after first position was changed to "False"
>>> 

Using this register_definitions:
{'ISTS': {'EXAMPLE_ISTS': {'register': 67, 'len': 1, 'val': 0}}, 'IREGS': {'EXAMPLE_IREG': {'register': 10, 'len': 2, 'val': 60001}}, 'HREGS': {'EXAMPLE_HREG': {'register': 93, 'len': 1, 'val': 19}}, 'COILS': {'EXAMPLE_COIL': {'register': 123, 'len': 3, 'val': [0, 1, 1]}}}

[brainelectronics]

Relates to #21 and #15 see also #18

[brainelectronics]

Relates to #36

[brainelectronics]

@beyonlo i think this issue can be closed as well after #33 was merged

[beyonlo]

@brainelectronics I don't thing so, because this problem still exists on the 2.1.0-rc15.dev39 version:

register_definitions = {
    "COILS": {
        "RESET_REGISTER_DATA_COIL": {
            "register": 42,
            "len": 1,
            "val": 0
        },
        "RESET_REGISTER_DATA_COIL_2": {
            "register": 45,
            "len": 1,
            "val": 0
        },
        "EXAMPLE_COIL": {
            "register": 123,
            "len": 16,
            "val": [1,0,0,1,1,0,1,1,1,1,1,1,1,1,0,1]
        },
...

Slave:

$ mpremote run tcp_client_example.py
Waiting for WiFi connection...
Waiting for WiFi connection...
Waiting for WiFi connection...
Waiting for WiFi connection...
Connected to WiFi.
('192.168.1.4', '255.255.255.0', '192.168.1.1', '192.168.1.1')
Setting up registers ...
Register setup done
Running ModBus version: 2.1.0-rc15.dev39
Serving as TCP client on 192.168.1.4:502

Master:

>>> from umodbus.tcp import TCP as ModbusTCPMaster
>>> host = ModbusTCPMaster(slave_ip='192.168.1.4', slave_port=502, timeout=5)
>>> from umodbus import version
>>> version.__version__
'2.1.0-rc15.dev39'
>>> host.read_coils(slave_addr=10, starting_addr=123, coil_qty=16)
[True, False, False, True, True, False, True, True, True, True, True, True, True, True, False, True]
>>> host.write_single_coil(slave_addr=10, output_address=123, output_value=0)
True
>>> host.read_coils(slave_addr=10, starting_addr=123, coil_qty=16)
[False, False, False, False, False, False, False, False] <---- Here all coils after first position was changed to "False"
>>> 

As the address 123 is a list of values with all 16 bits set. When I write just a single COIL (output_value=0) in that address happen:

1. Firstly that is not anymore 16 bits, but it turn to just 8 bits now
2. And that 8 bits now are all False

So, that is a problem right?

And there is a far relation with the #15 where I still curious how I do to write a single COIL in a different position than just first - that is default when I do output_value=0 right?

This will write a single COIL in the first bit on the address 123 right?
>>> host.write_single_coil(slave_addr=10, output_address=123, output_value=0)

How I do to write a single COIL in the second bit on the address 123?

Edit:

I see the new register usage docs, where the 0x05 write_single_coil talk about how to write single COIL just on the first position, but do not talk about how to write a COIL in a different position than the first one, like as the second position and so on.

[brainelectronics]

Relates to #35

[brainelectronics]

Fixed in 2.3.1