# Modbus float_abcd frame structure diagram

blockdiag mb_float_frame {
    # global properties
    span_width = 5;
    span_height = 5;
    node_height = 30;
    default_fontsize = 15;
    default_group_color = lightgrey;
    class spacer [shape=none, width=10];
    # tuning node properties and connections
    0,1,2 [class=spacer];
    0; note
    1; header
    2; response -- uid -- cmd -- len -- fl_abcd -- crc
    group float_abcd_packet {
        label = "PDU";
        color = gray;
        shape = line;
        style = dashed;
        group{uid,resp_uid};group{cmd,resp_cmd};group{len,resp_len};group{crc,resp_crc};
        group float_abcd{
            color = blue;
            shape = line;
            style = dashed;
            fl_abcd;dt_abcd;
        }
    }
    note[label="1: Unit Identificator, 2: Function code, 3: Data length, 4: Float data array, 5: Checksum",colwidth=6,color=lightyellow,shape=roundedbox]
    header[label="FLOAT_ABCD = 0x4640e400 = 12345.0",colwidth=6,color=lightgreen]
    response[label="RX:",color=yellow];
    uid[label="UID",numbered=1];cmd[label="FC",numbered=2];
    len[label="LENGTH",numbered=3];crc[label="CRC",numbered=5];
    resp_uid[label="0x01"];resp_cmd[label="0x03"];resp_len[label="0x08"];resp_crc[label="0x9065"];
    fl_abcd[label="FLOAT_ABCD",color=lightgreen,numbered=4];
    dt_abcd[label="0xE4004640",shape=note];
}