From 24587dfc2714ebfe4286235b250a3ca9fff77cfc Mon Sep 17 00:00:00 2001
From: Steve Karg <skarg@users.sourceforge.net>
Date: Thu, 26 Feb 2026 11:26:42 -0600
Subject: [PATCH] Add PROP_TIMER_RUNNING to writable properties and implement
 Timer_Running_Set functionality (#1245)

---
 CHANGELOG.md                              | 2 ++
 src/bacnet/basic/object/timer.c           | 8 ++++++++
 test/bacnet/basic/object/timer/src/main.c | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 190d1e06..a4b10183 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -52,6 +52,8 @@ The git repositories are hosted at the following sites:
 
 ### Added
 
+* Added PROP_TIMER_RUNNING to writable properties and implement
+  Timer_Running_Set functionality. (#1245)
 * Added BACNET_STACK_DEPRECATED_DISABLE guards around all of the deprecated
   decoding functions to ensure they are not used except intentionally for
   legacy code bases. (#1244)
diff --git a/src/bacnet/basic/object/timer.c b/src/bacnet/basic/object/timer.c
index b2ef5df9..2258b888 100644
--- a/src/bacnet/basic/object/timer.c
+++ b/src/bacnet/basic/object/timer.c
@@ -104,6 +104,7 @@ static const int32_t Properties_Proprietary[] = { -1 };
 static const int32_t Writable_Properties[] = {
     /* unordered list of always writable properties */
     PROP_PRESENT_VALUE,
+    PROP_TIMER_RUNNING,
     PROP_OUT_OF_SERVICE,
     PROP_DEFAULT_TIMEOUT,
     PROP_MIN_PRES_VALUE,
@@ -1955,6 +1956,13 @@ bool Timer_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
                 }
             }
             break;
+        case PROP_TIMER_RUNNING:
+            status = write_property_type_valid(
+                wp_data, &value, BACNET_APPLICATION_TAG_BOOLEAN);
+            if (status) {
+                Timer_Running_Set(wp_data->object_instance, value.type.Boolean);
+            }
+            break;
         case PROP_OUT_OF_SERVICE:
             status = write_property_type_valid(
                 wp_data, &value, BACNET_APPLICATION_TAG_BOOLEAN);
diff --git a/test/bacnet/basic/object/timer/src/main.c b/test/bacnet/basic/object/timer/src/main.c
index 4e0db131..8fae6ff2 100644
--- a/test/bacnet/basic/object/timer/src/main.c
+++ b/test/bacnet/basic/object/timer/src/main.c
@@ -55,6 +55,7 @@ static void test_Timer_Read_Write(void)
     uint32_t test_instance = 0;
     bool status = false;
     const int32_t skip_fail_property_list[] = { -1 };
+    const int32_t *writable_properties = NULL;
     BACNET_WRITE_PROPERTY_DATA wp_data = { 0 };
     BACNET_DEVICE_OBJECT_PROPERTY_REFERENCE member = { 0 }, *test_member = NULL;
     BACNET_APPLICATION_DATA_VALUE value = { 0 };
@@ -497,6 +498,8 @@ static void test_Timer_Read_Write(void)
     zassert_true(status, NULL);
     status = Timer_Description_Set(instance, NULL);
     zassert_true(status, NULL);
+    Timer_Writable_Property_List(instance, &writable_properties);
+    zassert_not_null(writable_properties, NULL);
     status = characterstring_init_ansi(&cstring, "");
     zassert_true(status, NULL);
     status =