diff --git a/Makefile b/Makefile
index f06b247..fdaf0cc 100644
--- a/Makefile
+++ b/Makefile
@@ -113,6 +113,7 @@ METER_OBJS:=\
 	$(BUILD)/meter_cma12w.o \
 	$(BUILD)/meter_q400.o \
 	$(BUILD)/meter_ehzp.o \
+	$(BUILD)/meter_esyswm.o \
 	$(BUILD)/printer.o \
 	$(BUILD)/serial.o \
 	$(BUILD)/shell.o \
diff --git a/README.md b/README.md
index 3108aab..b4eca0b 100644
--- a/README.md
+++ b/README.md
@@ -212,6 +212,7 @@ Elvaco CMa12w Thermometer (cma12w)
 Supported electricity meters:
 Tauron Amiplus (amiplus) (includes vendor apator and echelon)
 EMH Metering (ehzp)
+Easy Meter ESYS-WM20 (esyswm)
 
 Work in progress:
 Electricity meter Kamstrup Omnipower (omnipower)
diff --git a/src/dvparser.cc b/src/dvparser.cc
index 3027d90..73691b2 100644
--- a/src/dvparser.cc
+++ b/src/dvparser.cc
@@ -301,7 +301,7 @@ bool hasKey(std::map<std::string,std::pair<int,DVEntry>> *values, std::string ke
     return values->count(key) > 0;
 }
 
-bool findKey(MeasurementType mit, ValueInformation vif, int storagenr,
+bool findKey(MeasurementType mit, ValueInformation vif, int storagenr, int tariffnr,
              std::string *key, std::map<std::string,std::pair<int,DVEntry>> *values)
 {
     int low, hi;
@@ -316,13 +316,15 @@ bool findKey(MeasurementType mit, ValueInformation vif, int storagenr,
         MeasurementType ty = v.second.second.type;
         int vi = v.second.second.value_information;
         int sn = v.second.second.storagenr;
+        int tn = v.second.second.tariff;
         debug("(dvparser) match? %s type=%s vif=%02x (%s) and storagenr=%d\n",
               v.first.c_str(),
               measurementTypeName(ty).c_str(), vi, toString(toValueInformation(vi)), storagenr, sn);
 
         if (vi >= low && vi <= hi
             && (mit == MeasurementType::Unknown || mit == ty)
-            && (storagenr == ANY_STORAGENR || storagenr == sn))
+            && (storagenr == ANY_STORAGENR || storagenr == sn)
+            && (tariffnr == ANY_TARIFFNR || tariffnr == tn))
         {
             *key = v.first;
             debug("(dvparser) found key %s for type=%s vif=%02x (%s) storagenr=%d\n",
diff --git a/src/dvparser.h b/src/dvparser.h
index 506dbbe..2ba06c0 100644
--- a/src/dvparser.h
+++ b/src/dvparser.h
@@ -64,8 +64,11 @@ bool parseDV(Telegram *t,
 // find an existing difvif entry in the values based on the desired value information type.
 // Like: Volume, VolumeFlow, FlowTemperature, ExternalTemperature etc
 // in combination with the storagenr. (Later I will add tariff/subunit)
-bool findKey(MeasurementType mt, ValueInformation vi, int storagenr, std::string *key, std::map<std::string,std::pair<int,DVEntry>> *values);
+bool findKey(MeasurementType mt, ValueInformation vi, int storagenr, int tariffnr,
+             std::string *key, std::map<std::string,std::pair<int,DVEntry>> *values);
+
 #define ANY_STORAGENR -1
+#define ANY_TARIFFNR -1
 
 bool hasKey(std::map<std::string,std::pair<int,DVEntry>> *values, std::string key);
 
diff --git a/src/main.cc b/src/main.cc
index e94f247..08e46a8 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -302,7 +302,7 @@ LIST_OF_METERS
                 t.parserNoWarnings(); // Try a best effort parse, do not print any warnings.
                 t.parse(frame, &mk);
                 t.print();
-                t.explainParse("",0);
+                t.explainParse("(wmbus)",0);
                 logTelegram("(wmbus)", t.frame, 0, 0);
                 return true;
             });
diff --git a/src/meter_amiplus.cc b/src/meter_amiplus.cc
index 1fba839..dcd880b 100644
--- a/src/meter_amiplus.cc
+++ b/src/meter_amiplus.cc
@@ -120,12 +120,12 @@ void MeterAmiplus::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_energy_kwh_);
         t->addMoreExplanation(offset, " total energy (%f kwh)", total_energy_kwh_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::PowerW, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::PowerW, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &current_power_kw_);
         t->addMoreExplanation(offset, " current power (%f kw)", current_power_kw_);
     }
@@ -136,7 +136,7 @@ void MeterAmiplus::processContent(Telegram *t)
     extractDVdouble(&t->values, "0BAB3C", &offset, &current_power_returned_kw_);
     t->addMoreExplanation(offset, " current power returned (%f kw)", current_power_returned_kw_);
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         device_date_time_ = strdatetime(&datetime);
diff --git a/src/meter_apator162.cc b/src/meter_apator162.cc
index d6ee1d4..58f61e7 100644
--- a/src/meter_apator162.cc
+++ b/src/meter_apator162.cc
@@ -118,7 +118,7 @@ void MeterApator162::processContent(Telegram *t)
     vendor_values["0413"] = { 25, DVEntry(MeasurementType::Instantaneous, 0x13, 0, 0, 0, total) };
     int offset;
     string key;
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &vendor_values))
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &vendor_values))
     {
         extractDVdouble(&vendor_values, key, &offset, &total_water_consumption_m3_);
         //Adding explanation have to wait since it assumes that the dvparser could do something, but it could not here.
diff --git a/src/meter_cma12w.cc b/src/meter_cma12w.cc
index 00aa771..db02209 100644
--- a/src/meter_cma12w.cc
+++ b/src/meter_cma12w.cc
@@ -99,13 +99,13 @@ void MeterCMa12w::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 0, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &current_temperature_c_);
         t->addMoreExplanation(offset, " current temperature (%f C)", current_temperature_c_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &average_temperature_1h_c_);
         t->addMoreExplanation(offset, " average temperature 1h (%f C))", average_temperature_1h_c_);
diff --git a/src/meter_ehzp.cc b/src/meter_ehzp.cc
index 90dfa68..d929c33 100644
--- a/src/meter_ehzp.cc
+++ b/src/meter_ehzp.cc
@@ -22,7 +22,8 @@
 #include"wmbus_utils.h"
 #include"util.h"
 
-struct MeterEHZP : public virtual ElectricityMeter, public virtual MeterCommonImplementation {
+struct MeterEHZP : public virtual ElectricityMeter, public virtual MeterCommonImplementation
+{
     MeterEHZP(WMBus *bus, MeterInfo &mi);
 
     double totalEnergyConsumption(Unit u);
@@ -44,18 +45,10 @@ private:
 MeterEHZP::MeterEHZP(WMBus *bus, MeterInfo &mi) :
     MeterCommonImplementation(bus, mi, MeterType::EHZP, MANUFACTURER_EMH)
 {
-    setExpectedTPLSecurityMode(TPLSecurityMode::AES_CBC_IV);
+    setExpectedTPLSecurityMode(TPLSecurityMode::AES_CBC_NO_IV);
 
-    // This is one manufacturer of EHZP compatible meters.
-    addManufacturer(MANUFACTURER_APA);
     addMedia(0x02); // Electricity meter
 
-    // This is another manufacturer
-    addManufacturer(MANUFACTURER_DEV);
-    // Oddly, this device has not been configured to send as a electricity meter,
-    // but instead a device/media type that is used for gateway or relays or something?
-    addMedia(0x37); // Radio converter (meter side)
-
     addLinkMode(LinkMode::T1);
 
     setExpectedVersion(0x02);
@@ -113,16 +106,31 @@ double MeterEHZP::currentPowerProduction(Unit u)
 
 void MeterEHZP::processContent(Telegram *t)
 {
+    /*
+    (ehzp) 26: 07 dif (64 Bit Integer/Binary Instantaneous value)
+    (ehzp) 27: 00 vif (Energy mWh)
+    (ehzp) 28: * 583B740200000000 total energy (41.171800 kwh)
+    (ehzp) 30: 07 dif (64 Bit Integer/Binary Instantaneous value)
+    (ehzp) 31: 80 vif (Energy mWh)
+    (ehzp) 32: 3C vife (backward flow)
+    (ehzp) 33: * BCD7020000000000 total energy returned (0.186300 kwh)
+    (ehzp) 3b: 07 dif (64 Bit Integer/Binary Instantaneous value)
+    (ehzp) 3c: 28 vif (Power mW)
+    (ehzp) 3d: * B070200000000000 current power (2.126000 kw)
+    (ehzp) 45: 04 dif (32 Bit Integer/Binary Instantaneous value)
+    (ehzp) 46: 20 vif (On time seconds)
+    (ehzp) 47: * 92A40600 on time (120.929444 h)
+    */
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &total_energy_kwh_);
         t->addMoreExplanation(offset, " total energy (%f kwh)", total_energy_kwh_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::PowerW, 0, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::PowerW, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &current_power_kw_);
         t->addMoreExplanation(offset, " current power (%f kw)", current_power_kw_);
diff --git a/src/meter_esyswm.cc b/src/meter_esyswm.cc
new file mode 100644
index 0000000..292ec78
--- /dev/null
+++ b/src/meter_esyswm.cc
@@ -0,0 +1,249 @@
+/*
+ Copyright (C) 2020 Fredrik Öhrström
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include"dvparser.h"
+#include"meters.h"
+#include"meters_common_implementation.h"
+#include"wmbus.h"
+#include"wmbus_utils.h"
+#include"util.h"
+
+struct MeterESYSWM : public virtual ElectricityMeter, public virtual MeterCommonImplementation
+{
+    MeterESYSWM(WMBus *bus, MeterInfo &mi);
+
+    double totalEnergyConsumption(Unit u);
+    double totalEnergyConsumptionTariff1(Unit u);
+    double totalEnergyConsumptionTariff2(Unit u);
+    double currentPowerConsumption(Unit u);
+    double currentPowerConsumptionPhase1(Unit u);
+    double currentPowerConsumptionPhase2(Unit u);
+    double currentPowerConsumptionPhase3(Unit u);
+    double totalEnergyProduction(Unit u);
+    double currentPowerProduction(Unit u);
+
+private:
+
+    void processContent(Telegram *t);
+
+    double total_energy_kwh_ {};
+    double total_energy_tariff1_kwh_ {};
+    double total_energy_tariff2_kwh_ {};
+    double current_power_kw_ {};
+    double current_power_phase1_kw_ {};
+    double current_power_phase2_kw_ {};
+    double current_power_phase3_kw_ {};
+    double total_energy_returned_kwh_ {};
+    double current_power_returned_kw_ {};
+    string device_date_time_;
+};
+
+MeterESYSWM::MeterESYSWM(WMBus *bus, MeterInfo &mi) :
+    MeterCommonImplementation(bus, mi, MeterType::ESYSWM, 0)
+{
+    setExpectedTPLSecurityMode(TPLSecurityMode::AES_CBC_NO_IV);
+
+    addManufacturer(MANUFACTURER_EMH);
+
+    // The ESYS-WM-20 and ESYS-WM15 are addons to the electricity meters.
+    addMedia(0x37); // Radio converter (meter side)
+
+    addLinkMode(LinkMode::T1);
+
+    setExpectedVersion(0x30);
+
+    addPrint("total_energy_consumption", Quantity::Energy,
+             [&](Unit u){ return totalEnergyConsumption(u); },
+             "The total energy consumption recorded by this meter.",
+             true, true);
+
+    addPrint("current_power_consumption", Quantity::Power,
+             [&](Unit u){ return currentPowerConsumption(u); },
+             "Current power consumption.",
+             true, true);
+
+    addPrint("total_energy_production", Quantity::Energy,
+             [&](Unit u){ return totalEnergyProduction(u); },
+             "The total energy production recorded by this meter.",
+             true, true);
+
+    addPrint("total_energy_consumption_tariff1", Quantity::Energy,
+             [&](Unit u){ return totalEnergyConsumptionTariff1(u); },
+             "The total energy consumption recorded by this meter on tariff 1.",
+             false, true);
+
+    addPrint("total_energy_consumption_tariff2", Quantity::Energy,
+             [&](Unit u){ return totalEnergyConsumptionTariff2(u); },
+             "The total energy consumption recorded by this meter on tariff 2.",
+             false, true);
+
+    addPrint("current_power_consumption_phase1", Quantity::Power,
+             [&](Unit u){ return currentPowerConsumptionPhase1(u); },
+             "Current power consumption phase 1.",
+             false, true);
+
+    addPrint("current_power_consumption_phase2", Quantity::Power,
+             [&](Unit u){ return currentPowerConsumptionPhase2(u); },
+             "Current power consumption phase 2.",
+             false, true);
+
+    addPrint("current_power_consumption_phase3", Quantity::Power,
+             [&](Unit u){ return currentPowerConsumptionPhase3(u); },
+             "Current power consumption phase 3.",
+             false, true);
+
+}
+
+unique_ptr<ElectricityMeter> createESYSWM(WMBus *bus, MeterInfo &mi)
+{
+    return unique_ptr<ElectricityMeter>(new MeterESYSWM(bus, mi));
+}
+
+double MeterESYSWM::totalEnergyConsumption(Unit u)
+{
+    assertQuantity(u, Quantity::Energy);
+    return convert(total_energy_kwh_, Unit::KWH, u);
+}
+
+double MeterESYSWM::totalEnergyConsumptionTariff1(Unit u)
+{
+    assertQuantity(u, Quantity::Energy);
+    return convert(total_energy_tariff1_kwh_, Unit::KWH, u);
+}
+
+double MeterESYSWM::totalEnergyConsumptionTariff2(Unit u)
+{
+    assertQuantity(u, Quantity::Energy);
+    return convert(total_energy_tariff2_kwh_, Unit::KWH, u);
+}
+
+double MeterESYSWM::currentPowerConsumption(Unit u)
+{
+    assertQuantity(u, Quantity::Power);
+    return convert(current_power_kw_, Unit::KW, u);
+}
+
+double MeterESYSWM::currentPowerConsumptionPhase1(Unit u)
+{
+    assertQuantity(u, Quantity::Power);
+    return convert(current_power_phase1_kw_, Unit::KW, u);
+}
+
+double MeterESYSWM::currentPowerConsumptionPhase2(Unit u)
+{
+    assertQuantity(u, Quantity::Power);
+    return convert(current_power_phase2_kw_, Unit::KW, u);
+}
+
+double MeterESYSWM::currentPowerConsumptionPhase3(Unit u)
+{
+    assertQuantity(u, Quantity::Power);
+    return convert(current_power_phase3_kw_, Unit::KW, u);
+}
+
+double MeterESYSWM::totalEnergyProduction(Unit u)
+{
+    assertQuantity(u, Quantity::Energy);
+    return convert(total_energy_returned_kwh_, Unit::KWH, u);
+}
+
+double MeterESYSWM::currentPowerProduction(Unit u)
+{
+    assertQuantity(u, Quantity::Power);
+    return convert(current_power_returned_kw_, Unit::KW, u);
+}
+
+void MeterESYSWM::processContent(Telegram *t)
+{
+    /*
+      (esyswm) 2e: 07 dif (64 Bit Integer/Binary Instantaneous value)
+      (esyswm) 2f: 02 vif (Energy 10⁻¹ Wh)
+      (esyswm) 30: * F5C3FA0000000000 total energy (1643.416500 kwh)
+
+      (esyswm) 38: 07 dif (64 Bit Integer/Binary Instantaneous value)
+      (esyswm) 39: 82 vif (Energy 10⁻¹ Wh)
+      (esyswm) 3a: 3C vife (backward flow)
+      (esyswm) 3b: * 5407000000000000 total energy returned (0.187600 kwh)
+
+      (esyswm) 43: 84 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 44: 10 dife (subunit=0 tariff=1 storagenr=0)
+      (esyswm) 45: 04 vif (Energy 10¹ Wh)
+      (esyswm) 46: * E0810200 total energy tariff 1 (1643.200000 kwh)
+
+      (esyswm) 4a: 84 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 4b: 20 dife (subunit=0 tariff=2 storagenr=0)
+      (esyswm) 4c: 04 vif (Energy 10¹ Wh)
+      (esyswm) 4d: * 15000000 total energy tariff 2 (0.210000 kwh)
+
+      (esyswm) 51: 04 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 52: 29 vif (Power 10⁻² W)
+      (esyswm) 53: * 38AB0000 current power (0.438320 kw)
+
+      (esyswm) 57: 04 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 58: A9 vif (Power 10⁻² W)
+      (esyswm) 59: FF vife (additive correction constant: unit of VIF * 10^0)
+      (esyswm) 5a: 01 vife (?)
+      (esyswm) 5b: FA0A0000
+
+      (esyswm) 5f: 04 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 60: A9 vif (Power 10⁻² W)
+      (esyswm) 61: FF vife (additive correction constant: unit of VIF * 10^0)
+      (esyswm) 62: 02 vife (?)
+      (esyswm) 63: 050A0000
+
+      (esyswm) 67: 04 dif (32 Bit Integer/Binary Instantaneous value)
+      (esyswm) 68: A9 vif (Power 10⁻² W)
+      (esyswm) 69: FF vife (additive correction constant: unit of VIF * 10^0)
+      (esyswm) 6a: 03 vife (?)
+      (esyswm) 6b: 38960000
+    */
+    int offset;
+    string key;
+
+    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, 0, &key, &t->values)) {
+        extractDVdouble(&t->values, key, &offset, &total_energy_kwh_);
+        t->addMoreExplanation(offset, " total energy (%f kwh)", total_energy_kwh_);
+    }
+
+    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, 1, &key, &t->values)) {
+        extractDVdouble(&t->values, key, &offset, &total_energy_tariff1_kwh_);
+        t->addMoreExplanation(offset, " total energy tariff 1 (%f kwh)", total_energy_tariff1_kwh_);
+    }
+
+    if (findKey(MeasurementType::Unknown, ValueInformation::EnergyWh, 0, 2, &key, &t->values)) {
+        extractDVdouble(&t->values, key, &offset, &total_energy_tariff2_kwh_);
+        t->addMoreExplanation(offset, " total energy tariff 2 (%f kwh)", total_energy_tariff2_kwh_);
+    }
+
+    if (findKey(MeasurementType::Unknown, ValueInformation::PowerW, 0, 0, &key, &t->values)) {
+        extractDVdouble(&t->values, key, &offset, &current_power_kw_);
+        t->addMoreExplanation(offset, " current power (%f kw)", current_power_kw_);
+    }
+
+    extractDVdouble(&t->values, "07823C", &offset, &total_energy_returned_kwh_);
+    t->addMoreExplanation(offset, " total energy returned (%f kwh)", total_energy_returned_kwh_);
+
+    extractDVdouble(&t->values, "04A9FF01", &offset, &current_power_phase1_kw_);
+    t->addMoreExplanation(offset, " current power phase 1 (%f kwh)", current_power_phase1_kw_);
+
+    extractDVdouble(&t->values, "04A9FF02", &offset, &current_power_phase1_kw_);
+    t->addMoreExplanation(offset, " current power phase 2 (%f kwh)", current_power_phase2_kw_);
+
+    extractDVdouble(&t->values, "04A9FF03", &offset, &current_power_phase1_kw_);
+    t->addMoreExplanation(offset, " current power phase 3 (%f kwh)", current_power_phase3_kw_);
+
+}
diff --git a/src/meter_eurisii.cc b/src/meter_eurisii.cc
index 178bea0..161f2af 100644
--- a/src/meter_eurisii.cc
+++ b/src/meter_eurisii.cc
@@ -212,13 +212,13 @@ void MeterEurisII::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 0, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &current_consumption_hca_);
         t->addMoreExplanation(offset, " current consumption (%f hca)", current_consumption_hca_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, 0, &key, &t->values)) {
         struct tm date;
         extractDVdate(&t->values, key, &offset, &date);
         set_date_ = strdate(&date);
@@ -227,7 +227,7 @@ void MeterEurisII::processContent(Telegram *t)
 
     for (int i=1; i<=17; ++i)
     {
-        if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, i, &key, &t->values))
+        if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, i, 0, &key, &t->values))
         {
             string info;
             strprintf(info, " consumption at set date %d (%%f hca)", i);
diff --git a/src/meter_hydrodigit.cc b/src/meter_hydrodigit.cc
index 89bbfc2..bba1e69 100644
--- a/src/meter_hydrodigit.cc
+++ b/src/meter_hydrodigit.cc
@@ -68,12 +68,12 @@ void MeterHydrodigit::processContent(Telegram *t)
     int offset;
     string key;
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         meter_datetime_ = strdatetime(&datetime);
diff --git a/src/meter_hydrus.cc b/src/meter_hydrus.cc
index b873af5..8cf94bf 100644
--- a/src/meter_hydrus.cc
+++ b/src/meter_hydrus.cc
@@ -134,27 +134,27 @@ void MeterHydrus::processContent(Telegram *t)
     int offset;
     string key;
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &max_flow_m3h_);
         t->addMoreExplanation(offset, " max flow (%f m3/h)", max_flow_m3h_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::FlowTemperature, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::FlowTemperature, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &flow_temperature_c_);
         t->addMoreExplanation(offset, " flow temperature (%f °C)", flow_temperature_c_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 3, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 3, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_at_date_m3_);
         t->addMoreExplanation(offset, " total consumption at date (%f m3)", total_water_consumption_at_date_m3_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 3, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 3, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         at_date_ = strdatetime(&datetime);
diff --git a/src/meter_iperl.cc b/src/meter_iperl.cc
index 9a5a945..3ffb8a0 100644
--- a/src/meter_iperl.cc
+++ b/src/meter_iperl.cc
@@ -73,12 +73,12 @@ void MeterIperl::processContent(Telegram *t)
     int offset;
     string key;
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, ANY_STORAGENR, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, ANY_STORAGENR, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &max_flow_m3h_);
         t->addMoreExplanation(offset, " max flow (%f m3/h)", max_flow_m3h_);
     }
diff --git a/src/meter_lansenth.cc b/src/meter_lansenth.cc
index b522fe3..e22c81a 100644
--- a/src/meter_lansenth.cc
+++ b/src/meter_lansenth.cc
@@ -131,19 +131,19 @@ void MeterLansenTH::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 0, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &current_temperature_c_);
         t->addMoreExplanation(offset, " current temperature (%f C)", current_temperature_c_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &average_temperature_1h_c_);
         t->addMoreExplanation(offset, " average temperature 1h (%f C))", average_temperature_1h_c_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 2, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 2, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &average_temperature_24h_c_);
         t->addMoreExplanation(offset, " average temperature 24h (%f C))", average_temperature_24h_c_);
diff --git a/src/meter_multical21.cc b/src/meter_multical21.cc
index b56e1ff..7569541 100644
--- a/src/meter_multical21.cc
+++ b/src/meter_multical21.cc
@@ -307,30 +307,30 @@ void MeterMultical21::processContent(Telegram *t)
     extractDVuint16(&t->values, "02FF20", &offset, &info_codes_);
     t->addMoreExplanation(offset, " info codes (%s)", statusHumanReadable().c_str());
 
-    if(findKey(MeasurementType::Instantaneous, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Instantaneous, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         has_total_water_consumption_ = true;
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 1, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 1, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &target_water_consumption_m3_);
         has_target_water_consumption_ = true;
         t->addMoreExplanation(offset, " target consumption (%f m3)", target_water_consumption_m3_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, ANY_STORAGENR, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::VolumeFlow, ANY_STORAGENR, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &max_flow_m3h_);
         has_max_flow_ = true;
         t->addMoreExplanation(offset, " max flow (%f m3/h)", max_flow_m3h_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::FlowTemperature, ANY_STORAGENR, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::FlowTemperature, ANY_STORAGENR, 0, &key, &t->values)) {
         has_flow_temperature_ = extractDVdouble(&t->values, key, &offset, &flow_temperature_c_);
         t->addMoreExplanation(offset, " flow temperature (%f °C)", flow_temperature_c_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, ANY_STORAGENR, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, ANY_STORAGENR, 0, &key, &t->values)) {
         has_external_temperature_ = extractDVdouble(&t->values, key, &offset, &external_temperature_c_);
         t->addMoreExplanation(offset, " external temperature (%f °C)", external_temperature_c_);
     }
diff --git a/src/meter_multical302.cc b/src/meter_multical302.cc
index 4576a51..50c5d86 100644
--- a/src/meter_multical302.cc
+++ b/src/meter_multical302.cc
@@ -151,27 +151,27 @@ void MeterMultical302::processContent(Telegram *t)
     extractDVuint8(&t->values, "01FF21", &offset, &info_codes_);
     t->addMoreExplanation(offset, " info codes (%s)", status().c_str());
 
-    if(findKey(MeasurementType::Instantaneous, ValueInformation::EnergyWh, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Instantaneous, ValueInformation::EnergyWh, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_energy_kwh_);
         t->addMoreExplanation(offset, " total energy consumption (%f kWh)", total_energy_kwh_);
     }
 
-    if(findKey(MeasurementType::Instantaneous, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Instantaneous, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_volume_m3_);
         t->addMoreExplanation(offset, " total volume (%f m3)", total_volume_m3_);
     }
 
-    if(findKey(MeasurementType::Instantaneous, ValueInformation::EnergyWh, 1, &key, &t->values)) {
+    if(findKey(MeasurementType::Instantaneous, ValueInformation::EnergyWh, 1, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &target_energy_kwh_);
         t->addMoreExplanation(offset, " target energy consumption (%f kWh)", target_energy_kwh_);
     }
 
-    if(findKey(MeasurementType::Instantaneous, ValueInformation::PowerW, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Instantaneous, ValueInformation::PowerW, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &current_power_kw_);
         t->addMoreExplanation(offset, " current power consumption (%f kW)", current_power_kw_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         target_date_ = strdatetime(&datetime);
diff --git a/src/meter_q400.cc b/src/meter_q400.cc
index 8408661..9385495 100644
--- a/src/meter_q400.cc
+++ b/src/meter_q400.cc
@@ -100,17 +100,17 @@ void MeterQ400::processContent(Telegram *t)
     int offset;
     string key;
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 1, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 1, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &consumption_at_set_date_m3_);
         t->addMoreExplanation(offset, " consumption at set date (%f m3)", consumption_at_set_date_m3_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 1, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 1, 0, &key, &t->values)) {
         struct tm date;
         extractDVdate(&t->values, key, &offset, &date);
         set_date_ = strdate(&date);
diff --git a/src/meter_qcaloric.cc b/src/meter_qcaloric.cc
index 3d5a6c7..cc7ef78 100644
--- a/src/meter_qcaloric.cc
+++ b/src/meter_qcaloric.cc
@@ -169,29 +169,29 @@ void MeterQCaloric::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &current_consumption_hca_);
         t->addMoreExplanation(offset, " current consumption (%f hca)", current_consumption_hca_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 1, 0, &key, &t->values)) {
         struct tm date;
         extractDVdate(&t->values, key, &offset, &date);
         set_date_ = strdate(&date);
         t->addMoreExplanation(offset, " set date (%s)", set_date_.c_str());
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 1, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 1, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &consumption_at_set_date_hca_);
         t->addMoreExplanation(offset, " consumption at set date (%f hca)", consumption_at_set_date_hca_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 17, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::HeatCostAllocation, 17, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &consumption_at_set_date_17_hca_);
         t->addMoreExplanation(offset, " consumption at set date 17 (%f hca)", consumption_at_set_date_17_hca_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 17, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::Date, 17, 0, &key, &t->values)) {
         struct tm date;
         extractDVdate(&t->values, key, &offset, &date);
         set_date_17_ = strdate(&date);
@@ -206,7 +206,7 @@ void MeterQCaloric::processContent(Telegram *t)
         t->addMoreExplanation(offset, " error date (%s)", error_date_.c_str());
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         device_date_time_ = strdatetime(&datetime);
diff --git a/src/meter_rfmamb.cc b/src/meter_rfmamb.cc
index 3346e40..bdb8524 100644
--- a/src/meter_rfmamb.cc
+++ b/src/meter_rfmamb.cc
@@ -266,45 +266,45 @@ void MeterRfmAmb::processContent(Telegram *t)
     int offset;
     string key;
 
-    if (findKey(MeasurementType::Instantaneous, ValueInformation::ExternalTemperature, 0, &key, &t->values))
+    if (findKey(MeasurementType::Instantaneous, ValueInformation::ExternalTemperature, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &current_temperature_c_);
         t->addMoreExplanation(offset, " current temperature (%f C)", current_temperature_c_);
     }
 
-    if (findKey(MeasurementType::Maximum, ValueInformation::ExternalTemperature, 0, &key, &t->values))
+    if (findKey(MeasurementType::Maximum, ValueInformation::ExternalTemperature, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &maximum_temperature_1h_c_);
         t->addMoreExplanation(offset, " maximum temperature 1h (%f C)", maximum_temperature_1h_c_);
     }
 
-    if (findKey(MeasurementType::Minimum, ValueInformation::ExternalTemperature, 0, &key, &t->values))
+    if (findKey(MeasurementType::Minimum, ValueInformation::ExternalTemperature, 0, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &minimum_temperature_1h_c_);
         t->addMoreExplanation(offset, " minimum temperature 1h (%f C)", minimum_temperature_1h_c_);
     }
 
-    if (findKey(MeasurementType::Maximum, ValueInformation::ExternalTemperature, 1, &key, &t->values))
+    if (findKey(MeasurementType::Maximum, ValueInformation::ExternalTemperature, 1, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &maximum_temperature_24h_c_);
         t->addMoreExplanation(offset, " maximum temperature 24h (%f C)",
                               maximum_temperature_24h_c_);
     }
 
-    if (findKey(MeasurementType::Minimum, ValueInformation::ExternalTemperature, 1, &key, &t->values))
+    if (findKey(MeasurementType::Minimum, ValueInformation::ExternalTemperature, 1, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &minimum_temperature_24h_c_);
         t->addMoreExplanation(offset, " minimum temperature 24h (%f C)",
                               minimum_temperature_24h_c_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 1, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &average_temperature_1h_c_);
         t->addMoreExplanation(offset, " average temperature 1h (%f C)", average_temperature_1h_c_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 2, &key, &t->values))
+    if (findKey(MeasurementType::Unknown, ValueInformation::ExternalTemperature, 2, 0, &key, &t->values))
     {
         extractDVdouble(&t->values, key, &offset, &average_temperature_24h_c_);
         t->addMoreExplanation(offset, " average temperature 24h (%f C)", average_temperature_24h_c_);
@@ -369,7 +369,7 @@ void MeterRfmAmb::processContent(Telegram *t)
         t->addMoreExplanation(offset, " relative humidity 24h (%f RH)", average_relative_humidity_24h_rh_);
     }
 
-    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, &key, &t->values)) {
+    if (findKey(MeasurementType::Unknown, ValueInformation::DateTime, 0, 0, &key, &t->values)) {
         struct tm datetime;
         extractDVdate(&t->values, key, &offset, &datetime);
         device_date_time_ = strdatetime(&datetime);
diff --git a/src/meter_supercom587.cc b/src/meter_supercom587.cc
index 6d73cb3..0f8457e 100644
--- a/src/meter_supercom587.cc
+++ b/src/meter_supercom587.cc
@@ -66,7 +66,7 @@ void MeterSupercom587::processContent(Telegram *t)
     int offset;
     string key;
 
-    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, &key, &t->values)) {
+    if(findKey(MeasurementType::Unknown, ValueInformation::Volume, 0, 0, &key, &t->values)) {
         extractDVdouble(&t->values, key, &offset, &total_water_consumption_m3_);
         t->addMoreExplanation(offset, " total consumption (%f m3)", total_water_consumption_m3_);
     }
diff --git a/src/meters.h b/src/meters.h
index aa775b1..682e54a 100644
--- a/src/meters.h
+++ b/src/meters.h
@@ -30,7 +30,8 @@
     X(apator162,  C1_bit|T1_bit, Water,       APATOR162,   Apator162)    \
     X(cma12w,     C1_bit|T1_bit, TempHygro,   CMA12W,      CMa12w)       \
     X(eurisii,    T1_bit, HeatCostAllocation, EURISII, EurisII)   \
-    X(ehzp,       T1_bit, Water,       EHZP,        EHZP) \
+    X(ehzp,       T1_bit, Electricity, EHZP,        EHZP)         \
+    X(esyswm,     T1_bit, Electricity, ESYSWM,      ESYSWM)       \
     X(flowiq3100, C1_bit, Water,       FLOWIQ3100,  Multical21)   \
     X(hydrus,     T1_bit, Water,       HYDRUS,      Hydrus)       \
     X(hydrodigit, T1_bit, Water,       HYDRODIGIT,  Hydrodigit)   \
@@ -208,6 +209,7 @@ unique_ptr<TempHygroMeter> createLansenTH(WMBus *bus, MeterInfo &m);
 unique_ptr<TempHygroMeter> createCMa12w(WMBus *bus, MeterInfo &m);
 unique_ptr<TempHygroMeter> createRfmAmb(WMBus *bus, MeterInfo &m);
 unique_ptr<ElectricityMeter> createEHZP(WMBus *bus, MeterInfo &m);
+unique_ptr<ElectricityMeter> createESYSWM(WMBus *bus, MeterInfo &m);
 GenericMeter *createGeneric(WMBus *bus, MeterInfo &m);
 
 #endif
diff --git a/src/wmbus.cc b/src/wmbus.cc
index 64a340c..398edc4 100644
--- a/src/wmbus.cc
+++ b/src/wmbus.cc
@@ -1305,7 +1305,15 @@ bool Telegram::parseTPLConfig(std::vector<uchar>::iterator &pos)
             // If there is a tpl_counter, then use it, else use afl_counter.
             input.insert(input.end(), afl_counter_b, afl_counter_b+4);
             // If there is a tpl_id, then use it, else use ddl_id.
-            input.insert(input.end(), dll_id_b, dll_id_b+4);
+            if (tpl_id_found)
+            {
+                input.insert(input.end(), tpl_id_b, tpl_id_b+4);
+            }
+            else
+            {
+                input.insert(input.end(), dll_id_b, dll_id_b+4);
+            }
+
             // Pad.
             for (int i=0; i<7; ++i) input.insert(input.end(), 0x07);
 
@@ -1342,6 +1350,7 @@ bool Telegram::parseShortTPL(std::vector<uchar>::iterator &pos)
 
 bool Telegram::parseLongTPL(std::vector<uchar>::iterator &pos)
 {
+    tpl_id_found = true;
     tpl_id_b[0] = *(pos+0);
     tpl_id_b[1] = *(pos+1);
     tpl_id_b[2] = *(pos+2);
@@ -1518,6 +1527,7 @@ bool Telegram::parseTPL(vector<uchar>::iterator &pos)
 bool Telegram::parseHeader(vector<uchar> &input_frame)
 {
     bool ok;
+    explanations.clear();
     frame = input_frame;
     vector<uchar>::iterator pos = frame.begin();
     // Parsed accumulates parsed bytes.
@@ -1537,6 +1547,7 @@ bool Telegram::parseHeader(vector<uchar> &input_frame)
 
 bool Telegram::parse(vector<uchar> &input_frame, MeterKeys *mk)
 {
+    explanations.clear();
     meter_keys = mk;
     assert(meter_keys != NULL);
     bool ok;
@@ -1682,7 +1693,6 @@ bool Telegram::parse(vector<uchar> &input_frame, MeterKeys *mk)
 void Telegram::explainParse(string intro, int from)
 {
     for (auto& p : explanations) {
-        if (p.first < from) continue;
         debug("%s %02x: %s\n", intro.c_str(), p.first, p.second.c_str());
     }
     string hex = bin2hex(parsed);
diff --git a/src/wmbus.h b/src/wmbus.h
index 2ae0901..778eb1d 100644
--- a/src/wmbus.h
+++ b/src/wmbus.h
@@ -283,6 +283,7 @@ struct Telegram
     int tpl_kdf_selection {}; // 1 byte
     vector<uchar> tpl_generated_key; // 16 bytes
 
+    bool  tpl_id_found {}; // If set to true, then tpl_id_b contains valid values.
     uchar tpl_id_b[4]; // 4 bytes
     uchar tpl_mft_b[2]; // 2 bytes
     uchar tpl_version; // 1 bytes