modbus-rtu 1.3.1

Standard Modbus RTU protocols
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70

/// Errors that can occur while building a Modbus RTU request packet.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum RequestPacketError {
    /// This error is raised when the function tries to produce a request packet
    /// that exceeds the Modbus RTU protocol's maximum packet length of 256 bytes.
    ///
    /// Requests that attempt to write too many values at once will exceed
    /// the 256-byte limit of the request packet.
    ///
    /// ---
    ///
    /// If you intentionally need to bypass the request packet length limit,
    /// enable the Cargo feature as shown below.
    ///
    /// ## Warning: packets produced with this feature enabled may fail during communication.
    ///
    /// ```ignore
    /// [dependencies]
    /// modbus-rtu = { version = "1.0", features = ["unlimited_packet_size"] }
    /// ```
    ///
    RequestTooBig,

    /// This error is raised when the expected response packet would exceed the
    /// Modbus RTU protocol's maximum packet length of 256 bytes.
    ///
    /// ---
    ///
    /// If you intentionally need to bypass the response packet length limit,
    /// enable the Cargo feature as shown below.
    ///
    /// ## Warning: packets produced with this feature enabled may fail during communication.
    ///
    /// ```ignore
    /// [dependencies]
    /// modbus-rtu = { version = "1.0", features = ["unlimited_packet_size"] }
    /// ```
    ///
    ResponseWillTooBig,

    /// This error occurs when attempting to broadcast a function that does not
    /// support broadcasting (e.g., 0x01, 0x03).
    ///
    /// ---
    ///
    /// If you intentionally need to broadcast such functions, enable the Cargo
    /// feature as shown below.
    ///
    /// ## Warning: packets produced with this feature enabled may fail during communication.
    ///
    /// ```ignore
    /// [dependencies]
    /// modbus-rtu = { version = "1.0", features = ["enforce_broadcast"] }
    /// ```
    ///
    CannotBroadcast,
}

impl core::fmt::Display for RequestPacketError {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        let message = match self {
            Self::RequestTooBig => "request packet exceeds 256-byte.",
            Self::ResponseWillTooBig => "expected response packet exceeds 256-byte.",
            Self::CannotBroadcast => "this function does not support Modbus RTU broadcasting.",
        };
        f.write_str(message)
    }
}

impl core::error::Error for RequestPacketError {}