.getProtocolVersion() request packet format
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|=============================================================================
| byte \ bit   |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0
| 0          8+|                             zero
| 1          8+|                             zero
| 2          8+|                             pingData
|=============================================================================

==== Returns
protocolNum::
    The protocol number is a field that hints the host software if it should
    support the device. +
    +protocolNum = 2+ : Intended target SW is Logitech SetPoint +
    +protocolNum = 3+ : Intended OEM SW described in targetSw field +
    +protocolNum = 4+ : Intended target SW described in targetSw field

targetSw::
    When (+protocolNum >= 3+) this field further hints at which software
    should support the device. Otherwise the value is zero.

pingData::
    Echoes the ping paramenter as sent in the request. For recovery from
    timeouts or collisions.

.getProtocolVersion() response packet format
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|=============================================================================
| byte \ bit   |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0
| 0          8+|                          protocolNum
| 1          8+|                          targetSw
| 2          8+|                          pingData
|=============================================================================

[NOTE] On ping data usage: Ping data can be used by the SW to
re-synchronize the command/response data flow in case of collision or
timeout. Whenever an incorrect response is received or a command times out,
the SW should send a ping request and wait for a response with the correct
ping data. The ping data sent should be a random nonzero value which does
not match the previous ping request that was sent. If the SW is sending a
protocol request instead of a ping request the ping value should be 0

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|=============================================================================
| targetSw byte | bit 7 | bit 6 | bit 5 | bit 4 | bit 3 | bit 2 | bit 1 | bit 0
| meaning for
  protocol 4    | TSF   |  ---  |  ---  |  ---  |  ---  |  LPM  |  LGS  |  LDM
|=============================================================================

LDM:: Logitech Device Manager (Windows) is the intended target SW if
this bit is set.
LGS:: Logitech Gaming Software is the intended target SW if this bit is set.
LPM:: Logitech Preference (Mac) Manager is the intended target SW if
this bit is set.
TSF:: Target Software Feature: feature 0x0030 specifies the Target Software if
this bit is set.