It seems to be working well for me, I just pushed some changes, let me know if it's not working for you? I added some delay() here and there, it seems picky about that.
Verbose 17:52:08.850 port :COM Port: com15
Info 17:52:08.876 checksum :Checksum checking: True
Verbose 17:52:08.877 baud :BAUD rate: 115200
Verbose 17:52:08.878 address :Device address: 1
Verbose 17:52:08.879 get_voltage :Calling get_Mode from KP184
Verbose 17:52:08.879 get_voltage :Get voltage
Verbose 17:52:08.881 open :Opening serial port 'com15' at 115200 baud
Info 17:52:08.941 get_voltage :Voltage is 5924mV
Verbose 17:52:08.942 switch :Turning load switch on
Verbose 17:52:08.943 set_load_switch :Set switch on
Verbose 17:52:08.996 get_status :Calling get_status from KP184
Info 17:52:09.049 get_status :Status:
Info 17:52:09.050 get_status : Switch is on
Info 17:52:09.051 get_status : Mode is CC
Info 17:52:09.052 get_status : Current is 0
Info 17:52:09.053 get_status : Voltage is 5924
Info 17:52:09.055 ramp :Ramp: from 0 to 1000 in steps of 100 at intervals of 200
Verbose 17:52:09.056 set_current :Set current to 0mA
Info 17:52:09.109 ramp : 0mA, elapsed: 00:00:00.0531564
Verbose 17:52:09.256 set_current :Set current to 100mA
Info 17:52:09.309 ramp : 100mA, elapsed: 00:00:00.2534356
Verbose 17:52:09.456 set_current :Set current to 200mA
Info 17:52:09.508 ramp : 200mA, elapsed: 00:00:00.4522986
Verbose 17:52:09.656 set_current :Set current to 300mA
Info 17:52:09.709 ramp : 300mA, elapsed: 00:00:00.6532109
Verbose 17:52:09.856 set_current :Set current to 400mA
Info 17:52:09.908 ramp : 400mA, elapsed: 00:00:00.8521267
Verbose 17:52:10.056 set_current :Set current to 500mA
Info 17:52:10.109 ramp : 500mA, elapsed: 00:00:01.0532407
Verbose 17:52:10.256 set_current :Set current to 600mA
Info 17:52:10.313 ramp : 600mA, elapsed: 00:00:01.2576433
Verbose 17:52:10.456 set_current :Set current to 700mA
Info 17:52:10.510 ramp : 700mA, elapsed: 00:00:01.4544644
Verbose 17:52:10.657 set_current :Set current to 800mA
Info 17:52:10.710 ramp : 800mA, elapsed: 00:00:01.6546185
Verbose 17:52:10.857 set_current :Set current to 900mA
Info 17:52:10.911 ramp : 900mA, elapsed: 00:00:01.8551085
Verbose 17:52:11.057 set_current :Set current to 1000mA
Info 17:52:11.109 ramp : 1000mA, elapsed: 00:00:02.0531923
Verbose 17:52:11.257 get_voltage :Calling get_Mode from KP184
Verbose 17:52:11.258 get_voltage :Get voltage
Info 17:52:11.310 get_voltage :Voltage is 5922mV
Verbose 17:52:11.312 get_current :Calling get_Mode from KP184
Verbose 17:52:11.313 get_current :Get current
Info 17:52:11.365 get_current :Current is 787mA
Info 17:52:11.367 ramp :Ramp: from 1000 to 0 in steps of -100 at intervals of 200
Verbose 17:52:11.367 set_current :Set current to 1000mA
Info 17:52:11.419 ramp : 1000mA, elapsed: 00:00:00.0515168
Verbose 17:52:11.568 set_current :Set current to 900mA
Info 17:52:11.622 ramp : 900mA, elapsed: 00:00:00.2543872
Verbose 17:52:11.767 set_current :Set current to 800mA
Info 17:52:11.821 ramp : 800mA, elapsed: 00:00:00.4541509
Verbose 17:52:11.967 set_current :Set current to 700mA
Info 17:52:12.024 ramp : 700mA, elapsed: 00:00:00.6573842
Verbose 17:52:12.167 set_current :Set current to 600mA
Info 17:52:12.225 ramp : 600mA, elapsed: 00:00:00.8577865
Verbose 17:52:12.367 set_current :Set current to 500mA
Info 17:52:12.420 ramp : 500mA, elapsed: 00:00:01.0534372
Verbose 17:52:12.567 set_current :Set current to 400mA
Info 17:52:12.624 ramp : 400mA, elapsed: 00:00:01.2567874
Verbose 17:52:12.767 set_current :Set current to 300mA
Info 17:52:12.823 ramp : 300mA, elapsed: 00:00:01.4561288
Verbose 17:52:12.967 set_current :Set current to 200mA
Info 17:52:13.024 ramp : 200mA, elapsed: 00:00:01.6569999
Verbose 17:52:13.168 set_current :Set current to 100mA
Info 17:52:13.225 ramp : 100mA, elapsed: 00:00:01.8573013
Verbose 17:52:13.368 set_current :Set current to 0mA
Info 17:52:13.422 ramp : 0mA, elapsed: 00:00:02.0547666
Verbose 17:52:13.567 switch :Turning load switch off
Verbose 17:52:13.572 set_load_switch :Set switch off