Add device_status table for tracking device availability

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- New `device_status` table for tracking device operational status changes over time ([#242](https://github.com/TIDES-transit/TIDES/issues/242))
+    - Tracks when devices go offline, return to service, or experience errors
+    - Two timestamps: `record_timestamp` (when recorded) vs `status_change_timestamp` (when status actually changed)
+    - Supports data quality analysis by distinguishing missing data due to device outages from actual service patterns
+
 ## [1.0] - 2025-12-23
 
 ### Changed

samples/template/TIDES/datapackage.json

@@ -24,6 +24,20 @@
         }
     ],
     "resources": [
+        {
+            "name": "device_status",
+            "profile": "tabular-data-resource",
+            "path": "device_status.csv",
+            "schema": "https://raw.githubusercontent.com/TIDES-transit/TIDES/main/spec/device_status.schema.json",
+            "sources": [
+                {
+                    "title": "Where did data come from?",
+                    "component": "Type of technology component, e.g. `Device monitoring system`",
+                    "product": "Product used.",
+                    "vendor": "Vendor selling product."
+                }
+            ]
+        },
         {
             "name": "devices",
             "profile": "tabular-data-resource",

samples/template/TIDES/device_status.csv

@@ -0,0 +1 @@
+device_status_id,service_date,record_timestamp,status_change_timestamp,device_id,status_type,status_reason

spec/device_status.schema.json

@@ -0,0 +1,80 @@
+{
+  "primaryKey": "device_status_id",
+  "missingValues": [
+    "NA",
+    "NaN",
+    ""
+  ],
+  "fields": [
+    {
+      "name": "device_status_id",
+      "type": "string",
+      "title": "Device status ID",
+      "description": "Unique identifier for this device status record.",
+      "constraints": {
+        "required": true,
+        "unique": true
+      }
+    },
+    {
+      "name": "service_date",
+      "type": "date",
+      "title": "Service date",
+      "description": "Service date associated with this status record. Optional because device status may not align with transit service dates."
+    },
+    {
+      "name": "record_timestamp",
+      "type": "datetime",
+      "title": "Record timestamp",
+      "description": "Timestamp when this status record was created in the system. May differ from status_change_timestamp if status changes are recorded retroactively.",
+      "constraints": {
+        "required": true
+      }
+    },
+    {
+      "name": "status_change_timestamp",
+      "type": "datetime",
+      "title": "Status change timestamp",
+      "description": "Timestamp when the device status actually changed. This is the time the device went offline, came back online, or experienced the status change.",
+      "constraints": {
+        "required": true
+      }
+    },
+    {
+      "name": "device_id",
+      "type": "string",
+      "title": "ID referencing devices.device_id",
+      "description": "Identifies the device. References the devices table.",
+      "constraints": {
+        "required": true
+      }
+    },
+    {
+      "name": "status_type",
+      "type": "string",
+      "title": "Status type",
+      "description": "Type of device status. Examples: online, offline, maintenance, error, degraded. Agencies may define additional status types as needed.",
+      "constraints": {
+        "required": true
+      }
+    },
+    {
+      "name": "status_reason",
+      "type": "string",
+      "title": "Status reason",
+      "description": "Optional reason or description for the status change. Examples: scheduled maintenance, power failure, communication error, sensor malfunction."
+    }
+  ],
+  "foreignReferences": [
+    {
+      "fields": "device_id",
+      "reference": {
+        "resource": "devices",
+        "fields": "device_id"
+      }
+    }
+  ],
+  "name": "device_status.schema.json",
+  "description": "Records device operational status changes over time. This table tracks when devices (APCs, fare gates, AVL units, etc.) go offline, return to service, or experience errors. Enables data quality analysis by distinguishing between missing data due to device outages versus actual service patterns.",
+  "_table_type": "Event"
+}

spec/tides-datapackage-profile.json

@@ -293,6 +293,7 @@
           },
           "tides-table": {
             "enum": [
+              "device_status",
               "devices",
               "fare_transactions",
               "operators",