diff --git a/internal/module/m9zTtyApi/read.go b/internal/module/m9zTtyApi/read.go
index d8d62ad..6bce7db 100644
--- a/internal/module/m9zTtyApi/read.go
+++ b/internal/module/m9zTtyApi/read.go
@@ -158,8 +158,9 @@ func getDeviceStatus2Real(rpc towgo.JsonRpcConnection) {
 	d.DeviceStatus = *read
 	scanLoopCount := configuredLoopCount()
 	displayLoopCount := monitorDisplayLoopCount()
+	alarmDisplayEnabled := scanConfigManager.GetAlarmDisplayEnabled()
 	d.ScanDeviceCount = scanLoopCount
-	d.AlarmDisplayEnabled = scanConfigManager.GetAlarmDisplayEnabled()
+	d.AlarmDisplayEnabled = alarmDisplayEnabled
 	loops := make([]DeviceStatusLoop, displayLoopCount)
 	var wg sync.WaitGroup
 	for i := 0; i < displayLoopCount; i++ {
@@ -178,7 +179,7 @@ func getDeviceStatus2Real(rpc towgo.JsonRpcConnection) {
 				loop.A = parametersRead.DCCurrent
 				kw := float64(loop.V*loop.A) / 1000
 				loop.Kw = float32(math.Round(kw*1000) / 1000)
-				if idx < scanLoopCount {
+				if alarmDisplayEnabled && idx < scanLoopCount {
 					loop.Faults = m9z.BuildLoopFaults(uint(idx+1), parametersRead.AlarmStatus, parametersRead.AlarmCode)
 					loop.HasFault = len(loop.Faults) > 0
 					loop.FaultMsg = joinLoopFaultMessages(loop.Faults)
@@ -196,7 +197,7 @@ func getDeviceStatus2Real(rpc towgo.JsonRpcConnection) {
 		return d.Loops[i].Index < d.Loops[j].Index
 	})
 	for _, loop := range d.Loops {
-		if loop.HasFault && loop.Index < scanLoopCount {
+		if alarmDisplayEnabled && loop.HasFault && loop.Index < scanLoopCount {
 			recordLoopFaults(cuid, uint(loop.Index+1), loop.V, loop.Faults)
 		}
 	}
@@ -207,9 +208,10 @@ func getDeviceStatus2Real(rpc towgo.JsonRpcConnection) {
 func buildDemoDeviceStatus2() *DeviceStatus {
 	displayLoopCount := monitorDisplayLoopCount()
 	scanLoopCount := configuredLoopCount()
+	alarmDisplayEnabled := scanConfigManager.GetAlarmDisplayEnabled()
 	d := &DeviceStatus{
 		ScanDeviceCount:     scanLoopCount,
-		AlarmDisplayEnabled: scanConfigManager.GetAlarmDisplayEnabled(),
+		AlarmDisplayEnabled: alarmDisplayEnabled,
 		Loops:               make([]DeviceStatusLoop, displayLoopCount),
 	}
 	d.Mode = 0
@@ -233,7 +235,7 @@ func buildDemoDeviceStatus2() *DeviceStatus {
 		kw := float64(loop.V*loop.A) / 1000
 		loop.Kw = float32(math.Round(kw*1000) / 1000)
 
-		if i < scanLoopCount {
+		if alarmDisplayEnabled && i < scanLoopCount {
 			switch i {
 			case 0:
 				loop.Faults = m9z.BuildLoopFaults(uint(i+1), 0x01, "01 00")
diff --git a/internal/module/m9zTtyApi/scan_test.go b/internal/module/m9zTtyApi/scan_test.go
index 1ddef15..ccd88a8 100644
--- a/internal/module/m9zTtyApi/scan_test.go
+++ b/internal/module/m9zTtyApi/scan_test.go
@@ -76,4 +76,9 @@ func TestBuildDemoDeviceStatus2IncludesAlarmDisplayConfig(t *testing.T) {
 	if status.AlarmDisplayEnabled {
 		t.Fatal("status.AlarmDisplayEnabled = true, want false")
 	}
+	for _, loop := range status.Loops {
+		if loop.HasFault || loop.FaultMsg != "" || len(loop.Faults) > 0 {
+			t.Fatalf("loop %d still has fault data when alarm display disabled", loop.Index)
+		}
+	}
 }