diff --git a/Control/firmware/HendiCtrl/main.c b/Control/firmware/HendiCtrl/main.c
index 6c13220..ddc191c 100755
--- a/Control/firmware/HendiCtrl/main.c
+++ b/Control/firmware/HendiCtrl/main.c
@@ -212,31 +212,47 @@ int main(void)
 							else if (toupper(*pArgs) == 'R')
 							{
 								pArgs++;
-								if (!isdigit(*pArgs))
+								if ((*pArgs) == '?')
 								{
-									break;
+									pArgs++;
+									PRINT_ANSWER("OK:%d", (int)(state_next == StateRemote));
 								}
-								uint16_t arg = (uint16_t)strtol(pArgs, &pArgs, 10);
-								if (arg == 1)
+								else
 								{
-									// Enter remote
-									if (state == StateNormal)
+									if (!isdigit(*pArgs))
 									{
-										setPower(PowerLow);
-										setSwitch(SwitchOff);
-										state_next = StateRemote;
-										PRINT_ANSWER("OK");
+										break;
 									}
-								}
-								else if (arg == 0)
-								{
-									// Exit remote
-									if (state == StateRemote)
+									uint16_t arg = (uint16_t)strtol(pArgs, &pArgs, 10);
+									if (arg == 1)
 									{
-										setPower(PowerLow);
-										setSwitch(SwitchOff);
-										state_next = StateNormal;
-										PRINT_ANSWER("OK");
+										// Enter remote
+										if (state == StateNormal)
+										{
+											setPower(PowerLow);
+											setSwitch(SwitchOff);
+											state_next = StateRemote;
+											PRINT_ANSWER("OK");
+										}
+										else
+										{
+											PRINT_ANSWER("INVALID STATE");
+										}
+									}
+									else if (arg == 0)
+									{
+										// Exit remote
+										if (state == StateRemote)
+										{
+											setPower(PowerLow);
+											setSwitch(SwitchOff);
+											state_next = StateNormal;
+											PRINT_ANSWER("OK");
+										}
+										else
+										{
+											PRINT_ANSWER("INVALID STATE");
+										}
 									}
 								}
 							}
@@ -245,12 +261,20 @@ int main(void)
 							else if (toupper(*pArgs) == 'D')
 							{
 								pArgs++;
-								if (!isdigit(*pArgs))
+								if ((*pArgs) == '?')
 								{
-									break;
+									pArgs++;
+									PRINT_ANSWER("OK:%d", (int)(state_next == StateRemote));
+								}
+								else
+								{
+									if (!isdigit(*pArgs))
+									{
+										break;
+									}
+									g_debug = (uint16_t)strtol(pArgs, &pArgs, 10);
+									PRINT_ANSWER("OK");
 								}
-								g_debug = (uint16_t)strtol(pArgs, &pArgs, 10);
-								PRINT_ANSWER("OK");
 							}
 							
 							// SW identifier
@@ -291,6 +315,7 @@ int main(void)
 							else
 							{
 								pArgs++;
+								PRINT_ANSWER("UNKNOWN COMMAND");
 							}
 							
 						} // while (*pArgs)