func (this ModbusRTUConnection) ReadInputRegisters(slave int8, startAddr int, nb int) ([]uint16, error) {
if C.modbus_set_slave(this.ctx, C.int(slave)) != 0 {
return nil, errors.New(fmt.Sprintf("Invalid slave id %d", slave))
}
var space [65535]C.uint16_t
this.ProcessHook(RTU_03_LEN)
if ressived := C.modbus_read_input_registers(this.ctx, C.int(startAddr),
C.int(nb), &(space[0])); int(ressived) != nb {
if ressived == -1 {
errno := C.getErrno()
if errno == C.EMBMDATA {
return nil, errors.New(C.GoString(C.modbus_strerror(errno)))
}
return nil, errors.New(fmt.Sprintf("Unknown modbus error errno=%d", errno))
} else if ressived == 0 {
return nil, errors.New("No ansver ressived")
}
} else {
result := make([]uint16, ressived)
for i := 0; i < int(ressived); i++ {
result[i] = uint16(space[i])
}
return result, nil
}
return nil, nil
}
//The modbus_set_slave() function shall set the slave number in the libmodbus context.
//The behavior depends of network and the role of the device:
func (this *RtuConnection) Set_slave(slave uint8) error {
res, errno := C.modbus_set_slave(this.ctx, C.int(slave))
if int(res) != 0 {
this.curentSlave = INVALID_SLAVE
return errors.New(modbus_strerror(errno))
} else {
this.curentSlave = int16(slave)
return nil
}
}
func (this ModbusRTUConnection) WriteHolding(slave int8, addr int, value uint16) error {
if C.modbus_set_slave(this.ctx, C.int(slave)) != 0 {
return errors.New(fmt.Sprintf("Invalid slave id %d", slave))
}
this.ProcessHook(RTU_06_LEN)
if C.modbus_write_register(this.ctx, C.int(addr), C.int(value)) != 1 {
return errors.New(C.GoString(C.modbus_strerror(C.getErrno())))
}
return nil
}
func (this ModbusRTUConnection) WriteHoldings(slave int8, startAddr int, values []uint16) error {
if C.modbus_set_slave(this.ctx, C.int(slave)) != 0 {
return errors.New(fmt.Sprintf("Invalid slave id %d", slave))
}
vals := make([]C.uint16_t, len(values))
for i, v := range values {
vals[i] = C.uint16_t(v)
}
this.ProcessHook(RTU_10_LEN + len(values)*int(unsafe.Sizeof(vals[0])))
if C.modbus_write_registers(this.ctx, C.int(startAddr), C.int(len(values)), &vals[0]) < 0 {
return errors.New(C.GoString(C.modbus_strerror(C.getErrno())))
}
return nil
}
func (this ModbusRTUConnection) WriteSingleCoil(slave int8, addr int, value bool) error {
if C.modbus_set_slave(this.ctx, C.int(slave)) != 0 {
return errors.New(fmt.Sprintf("Invalid slave id %d", slave))
}
var v C.int
if value {
v = C.TRUE
}
this.ProcessHook(RTU_05_LEN)
if C.modbus_write_bit(this.ctx, C.int(addr), v) != 1 {
return errors.New(C.GoString(C.modbus_strerror(C.getErrno())))
}
return nil
}
func (this ModbusRTUConnection) WriteCoils(slave int8, startAddr int, values []bool) error {
if C.modbus_set_slave(this.ctx, C.int(slave)) != 0 {
return errors.New(fmt.Sprintf("Invalid slave id %d", slave))
}
vals := make([]C.uint8_t, len(values))
for i, v := range values {
if v {
vals[i] = C.TRUE
}
}
this.ProcessHook(RTU_0F_LEN + int(math.Ceil(float64(len(values))/8.0)))
if C.modbus_write_bits(this.ctx, C.int(startAddr), C.int(len(values)), &vals[0]) < 0 {
return errors.New(C.GoString(C.modbus_strerror(C.getErrno())))
}
return nil
}