Ejemplo n.º 1
0
    def fixed_pf(self, params=None):
        """ Get/set fixed power factor control settings.

        Params:
            Ena - Enabled (True/False)
            PF - Power Factor set point
            WinTms - Randomized start time delay in seconds
            RmpTms - Ramp time in seconds to updated output level
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for fixed factor.
        """
        if self.inv is None:
            der.DERError('DER not initialized')

        try:
            if params is not None:
                pf = params.get('PF')

                # Configuring Grid Management Services Control with Sunny Explorer
                # Cos phi (if supported by the device): Read Modbus register 30825. If the value 1075 can be read
                # from this register, the power factor is specified via system control.

                if pf is not None:
                    if pf > 0:
                        reg = 1042  # leading
                    else:
                        reg = 1041  # lagging
                    self.inv.write(40025, util.u32_to_data(int(reg)))

                    reg = int(abs(round(pf, 4) * 10000))
                    self.inv.write(40024, util.u16_to_data(int(reg)))

                ena = params.get('Ena')
                if ena is not None:
                    if ena is True:
                        reg = 1075  # 1075 = cos phi, specified by PV system control
                        # reg = 1074  # 1075 = cos phi, direct specific.
                    else:
                        reg = 303
                    if reg != util.data_to_u32(self.inv.read(40200, 2)):
                        self.inv.write(40200, util.u32_to_data(int(reg)))

            else:
                params = {}
                reg = self.inv.read(40200, 2)
                if util.data_to_u32(reg) == 1075:
                    params['Ena'] = True
                else:
                    params['Ena'] = False
                pf = None
                params['PF'] = pf
        except Exception, e:
            der.DERError(str(e))
Ejemplo n.º 2
0
    def limit_max_power(self, params=None):
        """ Get/set max active power control settings.

        Params:
            Ena - Enabled (True/False)
            WMaxPct - Active power maximum as percentage of WMax
            WinTms - Randomized start time delay in seconds
            RmpTms - Ramp time in seconds to updated output level
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for limit max power.
        """
        if self.inv is None:
            raise der.DERError('DER not initialized')

        #####  UNTESTED ####

        try:
            if params is not None:
                ena = params.get('Ena')
                if ena is not None:
                    if ena is True:
                        self.inv.write(40151, util.u32_to_data(802))
                    else:
                        self.inv.write(40151, util.u32_to_data(803))

                power = int(params.get('WMaxPct'))
                self.inv.write(
                    40016, util.s16_to_data(int(power))
                )  # Active power setpoint P, in % of the maximum active power (PMAX) of the inverter
                # self.inv.write(40023, util.s16_to_data(int(power)))  # Normalized active power limitation by PV system ctrl, in %
                # self.inv.write(40143, util.s32_to_data(int(power)))  # Active power setpoint for the operating mode "Active power limitation P via PV system control" (A)
                # self.inv.write(40147, util.u32_to_data(int(power)))  # Generator active power limitation for the operating mode "Active power limitation P via system control" (A)
                # self.inv.write(40149, util.s32_to_data(int(power)))  # Active power setpoint for the operating mode "Active power limitation P via system control" (W)

            else:
                params = {}
                if util.data_to_u32(self.inv.read(40151, 2)) == 803:
                    params['Ena'] = False
                else:
                    params['Ena'] = True
                params['WMaxPct'] = util.data_to_s16(self.inv.read(40016, 1))
                # params['WMaxPct'] = util.data_to_s16(self.inv.read(40023, 1))
                # params['WMaxPct'] = util.data_to_s32(self.inv.read(40143, 2))
                # params['WMaxPct'] = util.data_to_u32(self.inv.read(40147, 2))
                # params['WMaxPct'] = util.data_to_s32(self.inv.read(40149, 2))

        except Exception, e:
            raise der.DERError(str(e))
Ejemplo n.º 3
0
    def connect(self, params=None):
        """ Get/set connect/disconnect function settings.

        Params:
            Conn - Connected (True/False)
            WinTms - Randomized start time delay in seconds
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for connect.
        """

        if self.inv is None:
            raise der.DERError('DER not initialized')

        try:
            if params is not None:
                conn = params.get('Conn')
                if conn is not None:
                    if conn is True:
                        reg = 1467  # start
                    else:
                        reg = 1749  # Full stop (AC and DC side)
                        # reg = 381  # Stop (AC side)
                    self.inv.write(40018, util.u32_to_data(int(reg)))
            else:
                params = {}
                reg = self.inv.read(40018, 2)
                if util.data_to_u32(reg) == 1467:
                    params['Conn'] = True
                else:
                    params['Conn'] = False
        except Exception, e:
            raise der.DERError(str(e))
Ejemplo n.º 4
0
    def gridguard(self, new_gg=None):
        """ Read/Write SMA Grid Guard.

        Params:
            Grid Guard

        :return: 0 or 1 for GG off or on.
        """
        data = self.inv.read(43090, 2)
        gg = util.data_to_u32(data)
        if int(gg) == 1:
            self.ts.log("Grid Guard is already set")
            return True

        if new_gg is not None:
            self.ts.log('Writing new Grid Guard: %d' % new_gg)
            self.inv.write(43090, util.u32_to_data(int(new_gg)))

        self.ts.sleep(1)

        data = self.inv.read(43090, 2)
        gg = util.data_to_u32(data)
        self.ts.log("gg %s" % gg)
        if gg == 0:
            print('Grid guard was not enabled')
            return False
        else:
            print('Grid guard was enabled')
            return True
Ejemplo n.º 5
0
def test_run():

    result = script.RESULT_FAIL
    gsim = None

    ts.log_debug(' ')
    ts.log_debug(
        'Note: Please remove the Grid Guard Code from the test configuration after '
        'it has been to run to avoid exposing your Grid Guard Code to others.')
    ts.log_debug(' ')

    try:
        ipaddr = ts.param_value('gg.ipaddr')
        new_gg = ts.param_value('gg.code')
        # register = ts.param_value('gg.register')
        # port = ts.param_value('gg.port')
        # comm_id = ts.param_value('gg.id')

        register = 43090
        port = 502
        comm_id = 3

        if not new_gg or new_gg == 'None':
            raise script.ScriptFail('No Grid Guard Code specified.')

        device = client.ModbusClientDeviceTCP(comm_id, ipaddr, port)
        data = device.read(register, 2)
        gg = util.data_to_u32(data)
        ts.log('Current grid guard code: %s' % hex(gg))
        if gg == 0:
            ts.log('Original grid guard was not enabled')
        else:
            ts.log('Original grid guard was enabled')

        device.write(register, util.u32_to_data(int(new_gg)))
        data = device.read(register, 2)
        gg = util.data_to_u32(data)

        ts.log('Updated grid guard code: = %s' % hex(gg))
        if gg == 0:
            ts.log_warning('Current grid guard is not enabled')
            result = script.RESULT_FAIL
        else:
            ts.log('Current grid guard is enabled')
            result = script.RESULT_PASS

    except script.ScriptFail, e:
        reason = str(e)
        if reason:
            ts.log_error(reason)
Ejemplo n.º 6
0
    def gridguard(self, new_gg=None):
        """ Read/Write SMA Grid Guard.

        Params:
            Grid Guard

        :return: 0 or 1 for GG off or on.
        """

        if new_gg is not None:
            print('Writing new Grid Guard: %d' % new_gg)
            self.inv.write(43090, util.u32_to_data(int(new_gg)))

        data = self.inv.read(43090, 2)
        gg = util.data_to_u32(data)

        if gg == 0:
            print('Grid guard was not enabled')
            return False
        else:
            print('Grid guard was enabled')
            return True
Ejemplo n.º 7
0
def writeAdvancedPwrControlEn(control=True):
    if control:
        device.write(0xf142, util.u32_to_data(1))  # write power factor
    else:
        device.write(0xf142, util.u32_to_data(0))  # write power factor
    return readAdvancedPwrControlEn()
Ejemplo n.º 8
0
    def active_power(self, params=None):
        """ Get/set active power of EUT

        Params:
            Ena - Enabled (True/False)
            P - Active power in %Wmax (positive is exporting (discharging), negative is importing (charging) power)
            WinTms - Randomized start time delay in seconds
            RmpTms - Ramp time in seconds to updated output level
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for HFRT control.
        """
        if self.inv is None:
            raise der.DERError('DER not initialized')

        try:
            if params is not None:
                ena = params.get('Ena')
                if ena is not None:
                    if ena is True:
                        # self.inv.write(40151, util.u32_to_data(802))
                        self.inv.write(40210, util.u32_to_data(1078))
                    else:
                        # self.inv.write(40151, util.u32_to_data(803))
                        self.inv.write(40210, util.u32_to_data(303))
                        # Operating mode of active power limitation
                        # 303 = Off
                        # 1077 = Active power limitation P in W
                        # 1078 = Act. power lim. as % of Pmax
                        # 1079 = Act. power lim. via PV system ctrl
                        # 1390 = Active power limitation P via analogue input
                        # 1391 = Active power limitation P via digital inputs

                power = int(params.get('P'))
                # self.inv.write(40016, util.s16_to_data(int(power)))  # Active power setpoint P, in % of the maximum active power (PMAX) of the inverter
                # self.inv.write(40023, util.s16_to_data(int(power)))  # Normalized active power limitation by PV system ctrl, in %
                # self.inv.write(40143, util.s32_to_data(int(power)))  # Active power setpoint for the operating mode "Active power limitation P via PV system control" (A)
                # self.inv.write(40147, util.u32_to_data(int(power)))  # Generator active power limitation for the operating mode "Active power limitation P via system control" (A)
                # self.inv.write(40149, util.s32_to_data(int(power)))  # Active power setpoint for the operating mode "Active power limitation P via system control" (W)

                # self.inv.write(40212, util.u32_to_data(int(power)))  # Active power setpoint (W)
                self.inv.write(40214, util.u32_to_data(
                    int(power)))  # Active power setpoint (%)

            else:
                params = {}
                # enabled = util.data_to_u32(self.inv.read(40151, 1)) == 803
                enabled = util.data_to_u32(self.inv.read(40210, 1)) == 1078
                if enabled:
                    params['Ena'] = False
                else:
                    params['Ena'] = True
                # params['P'] = util.data_to_s16(self.inv.read(40016, 1))
                # params['P'] = util.data_to_s16(self.inv.read(40023, 1))
                # params['P'] = util.data_to_s32(self.inv.read(40143, 2))
                # params['P'] = util.data_to_u32(self.inv.read(40147, 2))
                # params['P'] = util.data_to_s32(self.inv.read(40149, 2))
                params['P'] = util.data_to_u32(self.inv.read(40214, 2))

        except Exception, e:
            raise der.DERError(str(e))
Ejemplo n.º 9
0
    def reactive_power(self, params=None):
        """ Set the reactive power

        Params:
            Ena - Enabled (True/False)
            Q - Reactive power as %Qmax (positive is overexcited, negative is underexcited)
            WinTms - Randomized start time delay in seconds
            RmpTms - Ramp time in seconds to updated output level
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for Q control.
        """

        # reactive_power_dept_ref = {
        #     'None': 0,
        #     'WMax': 1,
        #     'VArMax': 2,
        #     'VArAval': 3,
        #     0: 'None',
        #     1: 'WMax',
        #     2: 'VArMax',
        #     3: 'VArAval'
        # }

        if self.inv is None:
            raise der.DERError('DER not initialized')

        #####  UNTESTED ####

        try:
            if params is not None:
                ena = params.get('Ena')
                if ena is not None:
                    if ena is True:
                        # self.inv.write(40151, util.u32_to_data(802))
                        self.inv.write(40200, util.u32_to_data(1070))
                    else:
                        # self.inv.write(40151, util.u32_to_data(803))
                        self.inv.write(40200, util.u32_to_data(303))  #wanbin

                var_pct_mod = params.get('VArPct_Mod')
                if var_pct_mod is not None:
                    if var_pct_mod == 'WMax':
                        var_w_max_pct = int(params.get('VArWMaxPct'))
                        self.inv.write(40015,
                                       util.s16_to_data(int(var_w_max_pct)))
                        # self.inv.write(40153, util.s32_to_data(int(var_w_max_pct)))
                    else:
                        raise der.DERError(
                            'DER reactive power mode not supported')

            else:
                params = {}
                # enabled = util.data_to_u32(self.inv.read(40151, 1)) == 803
                enabled = util.data_to_u32(self.inv.read(
                    40200, 2)) == 1070  # Reactive power Q, direct spec.
                # enabled = util.data_to_u32(self.inv.read(40200, 2)) == 1071  # React. power const. Q in kvar
                if enabled:
                    params['Ena'] = False
                else:
                    params['Ena'] = True
                params['VArPct_Mod'] = 'WMax'
                params['VArWMaxPct'] = util.data_to_s16(self.inv.read(
                    40015, 1))
                # params['VArWMaxPct'] = util.data_to_s32(self.inv.read(40153, 2))
                # params['VArWMaxPct'] = util.data_to_s32(self.inv.read(40202, 2))  # Reactive power setpoint (VAr)
                params['VArWMaxPct'] = util.data_to_s32(
                    self.inv.read(40204, 2))  # Reactive power setpoint (%)

        except Exception, e:
            raise der.DERError(str(e))
Ejemplo n.º 10
0
    def volt_var_curve(self, id=1, params=None):
        """ Get/set volt/var curve
            v [] - List of voltage curve points
            var [] - List of var curve points based on DeptRef
            DeptRef - Dependent reference type: 'VAR_MAX_PCT', 'VAR_AVAL_PCT', 'VA_MAX_PCT', 'W_MAX_PCT'
            RmpTms - Ramp timer
            RmpDecTmm - Ramp decrement timer
            RmpIncTmm - Ramp increment timer

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for volt/var curve control.
        """
        if self.inv is None:
            raise der.DERError('DER not initialized')

        #x1 = range(40282, 40306, 2)  # X values 1 to 12 of the characteristic curve 1
        #y1 = range(40306, 40330, 2)  # Y values 1 to 12 of the characteristic curve 1

        x1 = [41077, 41081, 41085, 41089]  #wanbin
        y1 = [41079, 41083, 41087, 41091]  #wanbin
        '''
        x2 = range(40330, 40354, 2)  # X values 1 to 12 of the characteristic curve 2
        y2 = range(40354, 40378, 2)  # Y values 1 to 12 of the characteristic curve 2
        x3 = range(40378, 40402, 2)  # X values 1 to 12 of the characteristic curve 3
        y3 = range(40402, 40426, 2)  # Y values 1 to 12 of the characteristic curve 3
        '''
        volt_var_dept_ref = {
            'W_MAX_PCT': 1,
            'VAR_MAX_PCT': 2,
            'VAR_AVAL_PCT': 3,
            1: 'W_MAX_PCT',
            2: 'VAR_MAX_PCT',
            3: 'VAR_AVAL_PCT'
        }

        try:
            if int(id) > 3:
                raise der.DERError('Curve id out of range: %s' % id)

            if params is not None:
                # self.ts.log_debug('Writing VV Curve to SMA....')

                # set voltage points
                v = params.get('v')
                if v is not None:
                    v_len = len(v)
                    # if v_len > n_pt:
                    #     raise der.DERError('Voltage point count out of range: %d' % (v_len))

                    for i in xrange(v_len):  # SunSpec point index starts at 1
                        if id == 1:
                            v_val = int(
                                util.data_to_s32(self.inv.read(x1[i],
                                                               2)))  # read
                            self.ts.log_debug('Voltage point %s is %s' %
                                              (i, v_val))
                            if int(v_val) == int(round(v[i], 3) * 1000):
                                self.ts.log_debug(
                                    'V points : Skip Writing: Same setting')
                            else:
                                self.ts.log_debug(
                                    'Writing v point %s to reg %s with value %s'
                                    % (i, x1[i], v[i]))
                                self.inv.write(
                                    x1[i],
                                    util.s32_to_data(int(
                                        round(v[i], 3) * 1000)))
                                self.ts.log_debug('Wrote V points')
                        '''
                        elif id == 2:
                            self.inv.write(x2[i], util.s32_to_data(int(round(v[i], 3)*1000)))
                        else:
                            self.inv.write(x3[i], util.s32_to_data(int(round(v[i], 3)*1000)))
                        '''
                # set var points
                var = params.get('var')
                if var is not None:
                    var_len = len(var)
                    # if var_len > n_pt:
                    #     raise der.DERError('VAr point count out of range: %d' % (var_len))

                    self.inv.write(41075, util.u32_to_data(
                        1977))  # Var in percentages of Pmax #wanbin

                    for i in xrange(
                            var_len):  # SunSpec point index starts at 1
                        if id == 1:
                            var_val = int(
                                util.data_to_s32(self.inv.read(y1[i],
                                                               2)))  # read
                            if int(var_val) == int(round(var[i], 3) * 1000):
                                self.ts.log_debug(
                                    'VAR : Skip Writing: Same Setting')
                            else:
                                self.inv.write(
                                    y1[i],
                                    util.s32_to_data(
                                        int(round(var[i], 3) * 1000)))
                                self.ts.log_debug('Wrote Var points')
                        '''
                        elif id == 2:
                            self.inv.write(y2[i], util.s32_to_data(int(round(var[i], 3)*1000)))
                            self.inv.write(40979, util.u32_to_data(1977))  # Var in percentages of Pmax
                        else:
                            self.inv.write(y3[i], util.s32_to_data(int(round(var[i], 3)*1000)))
                            self.inv.write(40981, util.u32_to_data(1977))  # Var in percentages of Pmax
                        '''
            else:
                self.ts.log_debug('Reading VV curve in SMA')
                params = {}
                v = []
                var = []
                if id == 1:
                    n_pt = int(util.data_to_u32(self.inv.read(41071,
                                                              2)))  #wanbin
                    for i in xrange(int(4)):
                        self.ts.log('Getting V%s' % i)
                        v.append(
                            util.data_to_s32(self.inv.read(x1[i], 2)) / 1000.)
                        self.ts.log('Getting Q%s' % i)
                        var.append(
                            util.data_to_s32(self.inv.read(y1[i], 2)) / 1000.)
                '''
                elif id == 2:
                    n_pt = int(util.data_to_u32(self.inv.read(40264, 2)))
                    self.ts.log_debug('n_pt %s' % n_pt)
                    if n_pt < 1 or n_pt > 12:
                        raise der.DERError('Unsupported number of VV points. n_pt: %s' % n_pt)
                    for i in xrange(int(n_pt)):
                        v.append(util.data_to_s32(self.inv.read(x2[i], 2))/1000)
                        var.append(util.data_to_s32(self.inv.read(y2[i], 2))/1000)
                else:
                    n_pt = int(util.data_to_u32(self.inv.read(40266, 2)))
                    if n_pt < 1 or n_pt > 12:
                        raise der.DERError('Unsupported number of VV points. n_pt: %s' % n_pt)
                    for i in xrange(int(n_pt)):
                        v.append(util.data_to_s32(self.inv.read(x3[i], 2))/1000)
                        var.append(util.data_to_s32(self.inv.read(y3[i], 2))/1000)
                '''
                dept_ref = volt_var_dept_ref.get(1)  # 'W_MAX_PCT'
                params['DeptRef'] = dept_ref
                params['id'] = id  # also store the curve number
                params['v'] = v
                params['var'] = var

        except Exception, e:
            raise der.DERError(str(e))
Ejemplo n.º 11
0
    def volt_var(self, params=None):
        """ Get/set volt/var control

        Params:
            Ena - Enabled (True/False)
            ActCrv - Active curve number (0 - no active curve)
            NCrv - Number of curves supported
            NPt - Number of points supported per curve
            WinTms - Randomized start time delay in seconds
            RmpTms - Ramp time in seconds to updated output level
            RvrtTms - Reversion time in seconds

        :param params: Dictionary of parameters to be updated.
        :return: Dictionary of active settings for volt/var control.
        """
        if self.inv is None:
            raise der.DERError('DER not initialized')

        try:
            if params is not None:
                curve = params.get(
                    'curve'
                )  ## Must write curve first because there is a read() in volt_var_curve
                act_crv = params.get('ActCrv')

                if curve is not None:
                    self.volt_var_curve(id=act_crv, params=curve)

                ena = params.get('Ena')
                if ena is not None:
                    if ena is True:
                        reg = 2269  # React. power/volt. char. Q(U) #wanbin
                    else:
                        reg = 303
                    if reg != util.data_to_u32(self.inv.read(40200, 2)):
                        self.inv.write(40200, util.u32_to_data(int(reg)))

                    # Activation of the characteristic curve, configuration of characteristic curve mode
                    if ena is True:
                        reg = 308  # on
                    else:
                        reg = 303  # off

                    if reg != util.data_to_u32(self.inv.read(41063, 2)):
                        self.inv.write(41063, util.u32_to_data(
                            reg))  # Curve 1, 303 = off, 308 = on
                    if int(util.data_to_u32(self.inv.read(41061, 2))) != 2:
                        self.inv.write(41061, util.u32_to_data(
                            2))  # Curve 1, 303 = off, 308 = on
                    '''    
                    if act_crv == 1:
                        if reg != util.data_to_u32(self.inv.read(40937, 2)):
                            self.inv.write(40937, util.u32_to_data(reg))  # Curve 1, 303 = off, 308 = on
                    if act_crv == 2:
                        if reg != util.data_to_u32(self.inv.read(40939, 2)):
                            self.inv.write(40939, util.u32_to_data(reg))  # Curve 2, 303 = off, 308 = on
                    if act_crv == 3:
                        if reg != util.data_to_u32(self.inv.read(40941, 2)):
                            self.inv.write(40941, util.u32_to_data(reg))  # Curve 3, 303 = off, 308 = on
                    '''
                '''     
                if act_crv is not None:
                    # Characteristic curve number, configuration of the active power/voltage
                    # characteristic curve P(V). 0 = function is switched off.
                    if act_crv in [1, 2, 3]:
                        if act_crv != util.data_to_u32(self.inv.read(40260, 2)):
                            self.inv.write(40260, util.u32_to_data(act_crv))
                    else:
                        raise der.DERError('Unsupported characteristic curve number.')
                else:
                    # Q(U) programmed into curve 2 by default
                    act_crv = 2
                    if act_crv != util.data_to_u32(self.inv.read(40260, 2)):
                        self.inv.write(40260, util.u32_to_data(act_crv))
                '''
            else:
                params = {}
                self.ts.sleep(1)
                reg = self.inv.read(40200, 2)
                if int(util.data_to_u32(reg)) == 2269:
                    params['Ena'] = True
                else:
                    params['Ena'] = False
                    self.ts.log(util.data_to_u32(reg))

                params['ActCrv'] = 2
                '''
                if util.data_to_u32(self.inv.read(40937, 2)) == 303:
                    if util.data_to_u32(self.inv.read(40977, 2)) == 1977 and \
                       util.data_to_u32(self.inv.read(40957, 2)) == 1976:   # Voltage in %Vnom and Var in %Pmax
                            params['ActCrv'] = 1
                elif util.data_to_u32(self.inv.read(40937, 2)) == 303:
                    if util.data_to_u32(self.inv.read(40979, 2)) == 1977 and \
                       util.data_to_u32(self.inv.read(40959, 2)) == 1976:   # Voltage in %Vnom and Var in %Pmax
                            params['ActCrv'] = 2
                elif util.data_to_u32(self.inv.read(40937, 2)) == 303:
                    if util.data_to_u32(self.inv.read(40981, 2)) == 1977 and \
                       util.data_to_u32(self.inv.read(40961, 2)) == 1976:   # Voltage in %Vnom and Var in %Pmax
                            params['ActCrv'] = 3
                else:
                    params['ActCrv'] = None
                params['NCrv'] = 3  # SMA supports 3 curves
                if params['ActCrv'] is not None:
                    params['curve'] = self.volt_var_curve(id=params['ActCrv'])
                '''
        except Exception, e:
            der.DERError(str(e))
Ejemplo n.º 12
0
 def test_u32_to_data(self):
     self.assertEqual(util.u32_to_data(int(305419896)), b'\x12\x34\x56\x78')
     self.assertEqual(util.u32_to_data(int(2452903544)),
                      b'\x92\x34\x56\x78')
Ejemplo n.º 13
0
 def test_u32_to_data(self):
     self.assertEqual(util.u32_to_data(int(305419896)), b'\x12\x34\x56\x78')
     self.assertEqual(util.u32_to_data(int(2452903544)), b'\x92\x34\x56\x78')