core: Modbus incorrect reading multiple registers & swap: word & slave_count > 0

The problem

If the data of one sensor occupies more than one register, then when using “slave_count” > 0, the data is written to the sensors in reverse. For example, int32 occupies 2 registers: 6160 and 6161 Reading these registers we get: [AB][CD][EF][GH] After “swap: word” we get: [GH][EF][CD][AB]

Ok. But if we use this configuration:

  address: 6160
  slave_count: 2
  count: 6
  data_type: int32
  swap: word

Then we read 6 registers. And we get: [AB][CD][EF][GH] [IG][KL][MN][OP] [QR][ST][UV][XY] => [XY][UV][ST][QR] [OP][MN][KL][IG] [GH][EF][CD][AB] And the value that should be in the last sensor is written to the first sensor: [XY][UV][ST][QR] (from registers 6164, 6165) But it’s not right. The first sensor should have the value: [GH][EF][CD][AB] (from registers 6160, 6161) That is, we must divide the received data into an array (size of 1 element = data_type) and then do a swap word in a loop. This is only if slave_count > 0.

What version of Home Assistant Core has the issue?

core-2023.8.0

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant Supervised

Integration causing the issue

modbus

Link to integration documentation on our website

No response

Diagnostics information

No response

Example YAML snippet

- name: map12e_voltage_peak
  unique_id: map12e_voltage_peak
  scan_interval: 30
  slave: 46
  address: 6160
  slave_count: 2
  count: 6
  input_type: input
  data_type: int32
  scale: 0.01
  swap: word
  state_class: measurement
  device_class: voltage
  unit_of_measurement: V

Anything in the logs that might be useful for us?

No response

Additional information

No response