SLMP

SLMP is a protocol used for access from an external device to an SLMP-compatible device through the Ethernet. SLMP communications are available among devices that can transfer messages by SLMP. (personal computers, human machine interface and others.)

This project implements a client library that supports a subset of the functionality described in the SLMP reference manual, mainly regarding reading from and writing to Devices.

WARNING: I'd not advise you to use this library in production without testing your software throughly. Please implement proper security measures to mitigate any unintended consequences that using this library can cause. There are no unit tests as of now, use this library at your own risk.

Documentation

Auto-generated documentation with the help of Natural Docs.

Examples

Currently supported devices:

• D, W, R, ZR, SD
• X, Y, M, B, SM

Keep in mind that some of these devices might not be available for use on your targeted SLMP-compatible device.

Connecting to and Disconnecting from an SLMP Server

SlmpConfig cfg = new SlmpConfig("192.168.3.39", 6000) {
    ConnTimeout = 1000,
    RecvTimeout = 1000,
    SendTimeout = 1000,
};
SlmpClient plc = new SlmpClient(cfg);

plc.Connect();
plc.Disconnect();

Reading/writing into registers

There are a couple of ways to describe a read/write operation, you can either describe the target device with a string, e.g, "D200", "M200", "SD0" or directly with the Device enum. See the method prototypes below to get an idea of how the API operates.

bool ReadBitDevice(string addr)
bool ReadBitDevice(Device device, ushort addr)
bool[] ReadBitDevice(string addr, ushort count)
bool[] ReadBitDevice(Device device, ushort addr, ushort count)

ushort ReadWordDevice(string addr)
ushort ReadWordDevice(Device device, ushort addr)
ushort[] ReadWordDevice(string addr, ushort count)
ushort[] ReadWordDevice(Device device, ushort addr, ushort count)

string ReadString(string addr, ushort len)
string ReadString(Device device, ushort addr, ushort len)

void WriteBitDevice(string addr, bool data)
void WriteBitDevice(string addr, bool[] data)
void WriteBitDevice(Device device, ushort addr, bool data)
void WriteBitDevice(Device device, ushort addr, bool[] data)

void WriteWordDevice(string addr, ushort data)
void WriteWordDevice(string addr, ushort[] data)
void WriteWordDevice(Device device, ushort addr, ushort data)
void WriteWordDevice(Device device, ushort addr, ushort[] data)

void WriteString(string addr, string text)
void WriteString(Device device, ushort addr, string text)

Reading structures

public struct ExampleStruct {
    public bool boolean_word;              // 2 bytes, 1 word
    public int signed_double_word;         // 4 bytes, 2 words
    public uint unsigned_double_word;      // 4 bytes, 2 words
    public short short_signed_word;        // 2 bytes, 1 word
    public ushort ushort_unsigned_word;    // 2 bytes, 1 word
    [SlmpString(length = 6)]
    public string even_length_string;      // 6 bytes, 3 words (there's an extra 0x0000 right after the string in the plc memory)
    [SlmpString(length = 5)]
    public string odd_length_string;       // 5 bytes, 3 words (upper byte of the 3rd word is 0x00)
}

plc.ReadStruct<ExampleStruct>("D200");
// or
plc.ReadStruct<ExampleStruct>(Device.D, 200);

Funding

If you like this project and/or it's in any way useful to you, and you'd like to buy me a coffee, you can do it so from the link below!