diff --git a/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.cpp b/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ba7edf547d1d45873609d723b92934b18d7f5c88
--- /dev/null
+++ b/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.cpp
@@ -0,0 +1,146 @@
+#include "Reader.h"
+
+// STD / STL
+#include <algorithm>
+#include <cstring>
+#include <map>
+#include <optional>
+#include <ostream>
+#include <utility>
+#include <vector>
+
+#include <type_traits>
+
+// ICE
+#include <IceUtil/Handle.h>
+#include <IceUtil/Time.h>
+
+// Simox
+#include <SimoxUtility/algorithm/get_map_keys_values.h>
+
+// ArmarXCore
+#include "ArmarXCore/core/exceptions/LocalException.h"
+#include <ArmarXCore/core/exceptions/local/ExpressionException.h>
+#include <ArmarXCore/core/logging/LogSender.h>
+#include <ArmarXCore/core/logging/Logging.h>
+
+// RobotAPI Interfaces
+#include "RobotAPI/libraries/aron/converter/eigen/EigenConverter.h"
+#include <RobotAPI/interface/armem/mns/MemoryNameSystemInterface.h>
+#include <RobotAPI/interface/armem/server/ReadingMemoryInterface.h>
+#include <RobotAPI/interface/units/LaserScannerUnit.h>
+
+// RobotAPI Aron
+#include <RobotAPI/libraries/armem_vision/aron/OccupancyGrid.aron.generated.h>
+#include <RobotAPI/libraries/aron/core/Exception.h>
+#include <RobotAPI/libraries/aron/core/navigator/data/complex/NDArray.h>
+
+// RobotAPI Armem
+#include <RobotAPI/libraries/armem/client/Query.h>
+#include <RobotAPI/libraries/armem/client/Reader.h>
+#include <RobotAPI/libraries/armem/client/query/Builder.h>
+#include <RobotAPI/libraries/armem/client/query/selectors.h>
+#include <RobotAPI/libraries/armem/core/workingmemory/CoreSegment.h>
+#include <RobotAPI/libraries/armem/core/workingmemory/Entity.h>
+#include <RobotAPI/libraries/armem/core/workingmemory/EntityInstance.h>
+#include <RobotAPI/libraries/armem/core/workingmemory/Memory.h>
+#include <RobotAPI/libraries/armem/core/workingmemory/ProviderSegment.h>
+#include <RobotAPI/libraries/armem/util/util.h>
+#include <RobotAPI/libraries/armem_vision/aron/LaserScan.aron.generated.h>
+#include <RobotAPI/libraries/armem_vision/aron_conversions.h>
+#include <RobotAPI/libraries/armem_vision/types.h>
+
+namespace armarx::armem::vision::occupancy_grid::client
+{
+
+ armarx::armem::client::query::Builder Reader::buildQuery(const Query& query) const
+ {
+ armarx::armem::client::query::Builder qb;
+
+ // clang-format off
+ qb
+ .coreSegments().withName(properties().memoryName)
+ .providerSegments().withName(query.providerName)
+ .entities().all()
+ .snapshots().beforeOrAtTime(query.timestamp);
+ // clang-format on
+
+ return qb;
+ }
+
+ OccupancyGrid asOccupancyGrid(const std::map<std::string, wm::Entity>& entities)
+ {
+ ARMARX_CHECK(not entities.empty()) << "No entities";
+ ARMARX_CHECK(entities.size() == 1) << "There should be only one entity!";
+
+ const wm::Entity& entity = entities.begin()->second;
+ ARMARX_CHECK(not entity.empty()) << "No snapshots";
+
+ const auto& entitySnapshot = entity.getLatestSnapshot();
+ ARMARX_CHECK(not entitySnapshot.empty()) << "No entity snapshot instances";
+
+ const auto& entityInstance = entitySnapshot.instances().front();
+
+ const auto aronDto = tryCast<arondto::OccupancyGrid>(entityInstance);
+ ARMARX_CHECK(aronDto) << "Failed casting to OccupancyGrid";
+
+ OccupancyGrid occupancyGrid;
+ fromAron(*aronDto, occupancyGrid);
+
+ // direct access to grid data
+ const auto ndArrayNavigator = aron::datanavigator::NDArrayNavigator::DynamicCast(
+ entityInstance.data()->getElement("grid"));
+ ARMARX_CHECK_NOT_NULL(ndArrayNavigator);
+
+ occupancyGrid.grid = aron::converter::AronEigenConverter::ConvertToArray<float>(*ndArrayNavigator);
+
+ return occupancyGrid;
+ }
+
+ Reader::Result Reader::query(const Query& query) const
+ {
+ const auto qb = buildQuery(query);
+
+ ARMARX_IMPORTANT << "[MappingDataReader] query ... ";
+
+ const armem::client::QueryResult qResult =
+ memoryReader().query(qb.buildQueryInput());
+
+ ARMARX_DEBUG << "[MappingDataReader] result: " << qResult;
+
+ if (not qResult.success)
+ {
+ ARMARX_WARNING << "Failed to query data from memory: "
+ << qResult.errorMessage;
+ return {.occupancyGrid = std::nullopt,
+ .status = Result::Status::Error,
+ .errorMessage = qResult.errorMessage};
+ }
+
+ // now create result from memory
+ const auto& entities = qResult.memory.getCoreSegment(properties().memoryName)
+ .getProviderSegment(query.providerName)
+ .entities();
+
+ if (entities.empty())
+ {
+ ARMARX_WARNING << "No entities.";
+ return {.occupancyGrid = std::nullopt,
+ .status = Result::Status::NoData,
+ .errorMessage = "No entities"};
+ }
+
+ try
+ {
+ const auto occupancyGrid = asOccupancyGrid(entities);
+ return Result{.occupancyGrid = occupancyGrid,
+ .status = Result::Status::Success};
+ }
+ catch (...)
+ {
+ return Result{.status = Result::Status::Error,
+ .errorMessage = GetHandledExceptionString()};
+ }
+ }
+
+} // namespace armarx::armem::vision::occupancy_grid::client
diff --git a/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.h b/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.h
new file mode 100644
index 0000000000000000000000000000000000000000..a43c2c7c1151223358d5b1ab608f824fd3cdf66f
--- /dev/null
+++ b/source/RobotAPI/libraries/armem_vision/client/occupancy_grid/Reader.h
@@ -0,0 +1,74 @@
+/*
+ * This file is part of ArmarX.
+ *
+ * ArmarX is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * ArmarX 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/>.
+ *
+ * @author Fabian Reister ( fabian dot reister at kit dot edu )
+ * @date 2021
+ * @copyright http://www.gnu.org/licenses/gpl-2.0.txt
+ * GNU General Public License
+ */
+
+#pragma once
+
+#include <mutex>
+
+#include "RobotAPI/libraries/armem/client/util/SimpleReaderBase.h"
+#include "RobotAPI/libraries/armem/core/Time.h"
+#include "RobotAPI/libraries/armem_vision/types.h"
+#include <RobotAPI/libraries/armem/client/query/Builder.h>
+
+namespace armarx::armem::vision::occupancy_grid::client
+{
+
+ class Reader : virtual public armarx::armem::client::util::SimpleReaderBase
+ {
+ public:
+ using armarx::armem::client::util::SimpleReaderBase::SimpleReaderBase;
+ ~Reader() override;
+
+ struct Query
+ {
+ std::string providerName;
+ armem::Time timestamp;
+ };
+
+ struct Result
+ {
+ std::optional<OccupancyGrid> occupancyGrid = std::nullopt;
+
+ enum Status
+ {
+ Success,
+ NoData,
+ Error
+ } status;
+
+ std::string errorMessage = "";
+
+ operator bool() const noexcept
+ {
+ return status == Status::Success;
+ }
+ };
+
+ Result query(const Query& query) const;
+
+ ::armarx::armem::client::query::Builder buildQuery(const Query& query) const;
+
+ protected:
+ std::string propertyPrefix() const override;
+ Properties defaultProperties() const override;
+ };
+
+} // namespace armarx::armem::vision::occupancy_grid::client