diff --git a/sources/qetgraphicsitem/element.cpp b/sources/qetgraphicsitem/element.cpp
index a42f5ee64..f0d09639d 100644
--- a/sources/qetgraphicsitem/element.cpp
+++ b/sources/qetgraphicsitem/element.cpp
@@ -39,7 +39,9 @@
 #include "elementtextitemgroup.h"
 #include "iostream"
 
+#include <QApplication>
 #include <QCollator>
+#include <QScreen>
 
 static const QString plcTerminalKeys[] = {
 	QETInformation::ELMT_PLC_T1,
@@ -209,6 +211,21 @@ void Element::editProperty()
 		//with the "text" tab of ElementPropertiesWidget,
 		//the ui freeze, until user press escape key
 		dialog.setWindowModality(Qt::WindowModal);
+
+		// A PLC master carries a 6-column IO table: without an explicit
+		// size the dialog falls back to its (cramped) sizeHint, so open it
+		// at three times its natural width instead. The height stays at
+		// the natural one, and the width never exceeds the screen.
+		const ElementData data = elementData();
+		if (data.m_type == ElementData::Master
+			&& data.m_master_type == ElementData::PLC) {
+			const QSize natural = dialog.sizeHint();
+			int width = natural.width() * 3;
+			if (QScreen *screen = QApplication::primaryScreen())
+				width = qMin(width, screen->availableGeometry().width());
+			dialog.resize(width, natural.height());
+		}
+
 		dialog.exec();
 	}
 }
diff --git a/sources/ui/masterpropertieswidget.cpp b/sources/ui/masterpropertieswidget.cpp
index 339938d06..94d56e145 100644
--- a/sources/ui/masterpropertieswidget.cpp
+++ b/sources/ui/masterpropertieswidget.cpp
@@ -539,7 +539,35 @@ void MasterPropertiesWidget::updateUi()
 				tr("Type"), tr("Adresse"), tr("Fonction"),
 				tr("Commentaire"), tr("Réf. croisée"), tr("Bornes")
 			});
-			m_plc_table->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
+			m_plc_table->horizontalHeader()->setSectionResizeMode(QHeaderView::Interactive);
+			m_plc_table->horizontalHeader()->setSectionsMovable(true);
+			m_plc_table->horizontalHeader()->resizeSection(0, 120);
+			m_plc_table->horizontalHeader()->resizeSection(1, 100);
+			m_plc_table->horizontalHeader()->resizeSection(2, 150);
+			m_plc_table->horizontalHeader()->resizeSection(3, 150);
+			m_plc_table->horizontalHeader()->resizeSection(4, 100);
+			m_plc_table->horizontalHeader()->resizeSection(5, 120);
+
+			// Restore a previously saved column layout, if any
+			auto *plc_hdr = m_plc_table->horizontalHeader();
+			QSettings plc_settings;
+			const QVariant plc_hdr_state = plc_settings.value(
+				QStringLiteral("masterpropertieswidget/plc-table-header-state"));
+			if (!plc_hdr_state.isNull())
+				plc_hdr->restoreState(plc_hdr_state.toByteArray());
+
+			// Persist the column layout whenever the user resizes or moves a column
+			auto save_plc_header_state = [plc_hdr]()
+			{
+				QSettings settings;
+				settings.setValue(QStringLiteral("masterpropertieswidget/plc-table-header-state"),
+						  plc_hdr->saveState());
+			};
+			connect(plc_hdr, &QHeaderView::sectionResized,
+				this, save_plc_header_state);
+			connect(plc_hdr, &QHeaderView::sectionMoved,
+				this, save_plc_header_state);
+
 			m_plc_table->setSelectionBehavior(QAbstractItemView::SelectItems);
 			m_plc_table->setSelectionMode(QAbstractItemView::ExtendedSelection);
 			m_plc_table->setMinimumHeight(200);