Some fixes before the FAT

- Refactored inverter Heartbeat check
- Added SafetyComError on EtherCAT checking
- Adjusted lower pressure value for safety plc from 200 mBar to 300mBar

PLC/POUs/MAIN.TcPOU

@@ -147,6 +147,7 @@ VAR
 	_xStringsOff : BOOL;
 	_xStringsBalancingDone : BOOL;
 	_xStringsInAutoMode : BOOL;
+	_xStringSafetyComError : BOOL;
 	
 	_eStringOpMode : E_STRING_OPERATING_MODE;
 	
@@ -260,7 +261,7 @@ END_IF
 // Safety
 // ===============================
 xSafetyErrAck := xSafetyResterTaster;
-_xShowAckEmergencyStop := NOT _xEmergencyStopOk;
+_xShowAckEmergencyStop := (NOT _xEmergencyStopOk) OR _xStringSafetyComError;
 
 IF (NOT _xEmergencyStopOk) AND (NOT _fbEStopNotOk.bRaised) THEN
 	_fbEStopNotOk.Raise(0);
@@ -396,8 +397,15 @@ _rSmallestSegmentVoltage := 1_000.0;
 _xStringsInAutoMode := TRUE;
 _uiNumberOfActiveStrings := 0;
 _rStringsSumVoltage := 0;
+_xStringSafetyComError := FALSE;
 
 FOR _ui := 0 TO (GVL_CONFIG.uiNumberOfStrings-1) DO
+	// Check for safety com error
+	IF _afbStrings[_ui].xSafetyComError THEN
+		_xStringSafetyComError := TRUE;
+	END_IF	
+
+
 	// Ignore deactivated strings
 	IF (NOT GVL_CONFIG.axStringEnabled[_ui]) THEN
 		CONTINUE;