Debug shows unsigned bytes as signed (minor issue)

Hello, minor puzzle here, I set parameter 11 of my Fibaro multisensor (switches and temperatures, mains operated) to 255, its max value, as defined in the database’s XML;

    "id": 11,
    "label": "Interval betw. forcing to send report for temp.",
    "description": "The forced report is sent immediately after ...",
    "overview": "<p>... the next reading of temperature from the sensor, irrespective of the settings<br \/>of parameter no. 12.<br \/>Default value: 200 s<br \/>Possible parameter settings:<br \/>0 \u2013 255 s<br \/>0 \u2013 deactivating the function<br \/>Note: Frequent sending of temperature condition reports is<br \/>reasonable when the sensor is located somewhere where can<br \/>occure rapid changes of ambient temperature. In other cases<br \/>it is recommended to leave the parameter set to the default<br \/>value.<\/p>",
    "size": 1,
    "bitmask": "00000000",
    "default": 200,
    "read_only": false,
    "write_only": false,
    "value_min": 1,
    "value_max": 255,
    "options": []

This was reported in the debug as the value being set to “-1” which caused me some minor confusion. Setting the variable to 254 showed in the debug as -2.

NODE 41: Node configuration report, parameter = 11, value = -1, size = 1

Pretty minor but just flagging it up in case it’s indicative of anything else.

dbReference 126
defaultAssociations 3
manufacturerId 010F
manufacturerRef 0501:0102,0501:0109,0501:1002,0501:2002,0501:3002,0501:4002
modelId FGBS001
vendor Fibargroup