92 lines
2.1 KiB
Go
92 lines
2.1 KiB
Go
package main
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import (
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"math"
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"strconv"
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"time"
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"actshad.dev/modbus"
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)
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var (
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modbus_client modbus.Client
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sample_cache sampleCache
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)
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func modbus_is_connected() bool {
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return modbus_client != nil
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}
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// Read modbus register and convert result into float
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func modbus_read_float_register(register_address uint16) (float32, error) {
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var result float32 = 0.0
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if modbus_client != nil {
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res, err := modbus_client.ReadInputRegisters(register_address, 2)
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if err != nil {
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logger.Print("Modbus connection lost")
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modbus_client = nil
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return 0.0, err
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}
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var ieee754 uint32 = (uint32(res[0])<<24 + (uint32(res[1]) << 16) + (uint32(res[2]) << 8) + uint32(res[3]))
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result = math.Float32frombits(ieee754)
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}
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return result, nil
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}
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// Connect to modbus tcp bridge
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func modbus_connect(host string, port uint, slave_id byte) error {
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connection := host + ":" + strconv.FormatUint(uint64(port), 10)
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handler := modbus.NewTCPClientHandler(connection)
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handler.Timeout = 10 * time.Second
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handler.SlaveId = slave_id
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err := handler.Connect()
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if err != nil {
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logger.Print(err)
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return err
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}
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logger.Print("Modbus connected")
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defer handler.Close()
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modbus_client = modbus.NewClient(handler)
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return nil
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}
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// connect to modbus tcp bridge host. If connection is lost try to re-connect.
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func keep_mbus_connection() {
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for { // ever
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time.Sleep(time.Second)
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if !modbus_is_connected() {
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modbus_connect(config_cache.ModbusHost,
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uint(config_cache.ModbusPort),
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byte(config_cache.RtuAddress),
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)
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}
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}
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}
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// Collect data of SDM-630 power meter
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func collect_mbus_samples() {
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for { // ever
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if modbus_is_connected() {
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sample := make(map[string]measure)
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for key, register := range sdm_registers {
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res, err := modbus_read_float_register(register.Address)
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if err != nil {
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logger.Printf("Could not read from %s (%s)", key, err)
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continue
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}
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var mes measure
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mes.Value = res
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mes.Unit = register.Unit
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sample[key] = mes
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}
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sample_cache.mutex.Lock()
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sample_cache.sample = sample
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sample_cache.mutex.Unlock()
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}
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time.Sleep(time.Duration(config_cache.SampleRate * 1000000000))
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}
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}
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