Use the brake terminal diagnostic input

Adds the diagnostic input signal to the external brake code to prevent
unwanted motion when the diagnostic input fails. Since the input
variable defaults to TRUE, it is still possible to use the external
brake functionality without connecting the diagnostic input variable to
any I/O.

Author: mac-kan

POUs/Motion/FB_Axis.TcPOU

@@ -527,6 +527,7 @@ CASE eExternalBrake OF
         IF TON_DelayBrakeRelease.Q THEN
             IF NOT _stAxis.stStatus.bEnabled
                 OR _stAxis.stStatus.bError
+                OR NOT _stAxis.stInputs.bBrakeTerminalDiagnosticsOk
                 OR TON_BrakeOpeningTimeoutWhenFeedback.Q THEN
                 _stAxis.stControl.bEnable := FALSE;
                 _stAxis.stControl.bReleaseBrake := FALSE;
@@ -538,6 +539,7 @@ CASE eExternalBrake OF
             END_IF
 
             IF _stAxis.stControl.bReleaseBrake
+                AND _stAxis.stInputs.bBrakeTerminalDiagnosticsOk
                 AND ((_stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected
                     AND _stAxis.stInputs.bBrakeReleased)
                 OR NOT _stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected) THEN
@@ -571,9 +573,10 @@ CASE eExternalBrake OF
             _stAxis.stControl.bEnable := FALSE;
             bEnableAmp := FALSE;
             eExternalBrake := E_ExternalBrake.eBrakeEngaged;
-        ELSIF _stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected
-            AND _stAxis.stControl.bReleaseBrake
-            AND NOT _stAxis.stInputs.bBrakeReleased THEN
+        ELSIF ((_stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected
+                AND NOT _stAxis.stInputs.bBrakeReleased)
+            OR NOT _stAxis.stInputs.bBrakeTerminalDiagnosticsOk)
+            AND _stAxis.stControl.bReleaseBrake THEN
             _stAxis.stControl.bReleaseBrake := FALSE;
             _stAxis.stControl.bEnable := FALSE;
             bEnableAmp := FALSE;
@@ -607,6 +610,7 @@ END_CASE
 
 bReady :=
     eExternalBrake = E_ExternalBrake.eBrakeReleased
+    AND _stAxis.stInputs.bBrakeTerminalDiagnosticsOk
     AND ((_stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected
         AND _stAxis.stInputs.bBrakeReleased)
     OR NOT _stAxis.stConfig.stAirpadBrake.bExternalBrakeFeedbackConnected);