bug

warewms-hard/src/main/java/com/ruoyi/hard/modbus/tcp/ButtonBoxClient.java

@@ -186,6 +186,9 @@ public class ButtonBoxClient {
     private short read(int slaveId, int offset, int len) {
         ModbusMasterUtil modbusMasterUtil = modbusTcpMasterTemplateThird.getModbusMasterUtil();
         ReadResponse readResponse = modbusMasterUtil.readHoldingRegisters(slaveId, offset, len);
+        if (readResponse == null) {
+            return 0;
+        }
         short[] shortData = readResponse.getShortData();
         return shortData[0];
     }