Coil quantity specification does not work

[brainelectronics]

As found out during #10 the coil_qty parameter of the read_coils function of TCP and RTU is not working.

host.read_coils(slave_addr=10, starting_addr=123, coil_qty=1)
# [True, False, False, False, False, False, False, False]   # <--- "coil_qty=1" but showed 8 and not just 1.
host.read_coils(slave_addr=10, starting_addr=123, coil_qty=20)
# [True, False, False, False, False, False, False, False]   # <--- "coil_qty=20" but still showing 8, and not 20.

[javiercp64]

And only the first coil value is correct, the others always appears as false.

[beyonlo]

And only the first coil value is correct, the others always appears as false.

That's correct @javiercp64 for default definitions example because the len is 1 ("len": 1) for the value 1 ("val": 1), so others bits that are not set, are 0 (False) by default.

If you change the definitions to set others bit values you will receive True if you set as 1. See example below with new definitions - look at "val":

register_definitions = { "COILS": { "EXAMPLE_COIL": { "register": 123, "len": 3, "val": [1, 0, 1] } },

Output:

>>> host.read_coils(slave_addr=10, starting_addr=123, coil_qty=3)
[True, False, True, False, False, False, False, False]
>>>

However, the write multiple COILS has a bug, as reported on the PR #10, in this section, item 2.

[beyonlo]

As detected by @brainelectronics on the thread https://github.com/brainelectronics/micropython-modbus/pull/10#issuecomment-1203521346 is correct to return always multiple of 8 bits. So is correct when coil_qty=1 returning the 8 bits/elements. But the bug still exists, once that coil_qty=20 is returning just first 8 bits.

host.read_coils(slave_addr=10, starting_addr=123, coil_qty=1)
[True, False, False, False, False, False, False, False]   # CORRECT: "coil_qty=1"  and showed 8 bits (multiple of 8).
host.read_coils(slave_addr=10, starting_addr=123, coil_qty=20)
[True, False, False, False, False, False, False, False]   # NOT CORRECT: "coil_qty=20" showing only first 8 bits.

[brainelectronics]

@brainelectronics Check Implementation to follow requirement of returning multiple coils as requested, see http://www.simplymodbus.ca/FC01.htm

[brainelectronics]

https://github.com/brainelectronics/micropython-modbus/compare/develop...ShaunL36:micropython-modbus:develop

[brainelectronics]

related to #25

[brainelectronics]

https://github.com/brainelectronics/micropython-modbus/commit/220d3b9ea84cb5c913168e64dddd7f2c6ab9e7c5