diff --git a/examples/device/usbtmc/src/main.c b/examples/device/usbtmc/src/main.c
index 0293261ad..8bc2a8398 100644
--- a/examples/device/usbtmc/src/main.c
+++ b/examples/device/usbtmc/src/main.c
@@ -36,12 +36,12 @@
 
 /* Blink pattern
  * - 250 ms  : device not mounted
- * - 1000 ms : device mounted
+ * - 0 ms : device mounted
  * - 2500 ms : device is suspended
  */
 enum  {
   BLINK_NOT_MOUNTED = 250,
-  BLINK_MOUNTED = 1000,
+  BLINK_MOUNTED = 0,
   BLINK_SUSPENDED = 2500,
 };
 
@@ -97,17 +97,46 @@ void tud_resume_cb(void)
 }
 
 //--------------------------------------------------------------------+
-// BLINKING TASK
+// BLINKING TASK + Indicator pulse
 //--------------------------------------------------------------------+
+
+
+volatile uint8_t doPulse = false;
+// called from USB context
+void led_indicator_pulse(void) {
+	doPulse = true;
+}
+
 void led_blinking_task(void)
 {
   static uint32_t start_ms = 0;
   static bool led_state = false;
+  if(blink_interval_ms == BLINK_MOUNTED) // Mounted
+  {
+    if(doPulse)
+    {
+      led_state = true;
+      board_led_write(true);
+      start_ms = board_millis();
+      doPulse = false;
+    }
+    else if (led_state == true)
+    {
+      if ( board_millis() - start_ms < 750) //Spec says blink must be between 500 and 1000 ms.
+      {
+        return; // not enough time
+      }
+      led_state = false;
+      board_led_write(false);
+    }
+  }
+  else
+  {
+    // Blink every interval ms
+    if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
+    start_ms += blink_interval_ms;
 
-  // Blink every interval ms
-  if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
-  start_ms += blink_interval_ms;
-
-  board_led_write(led_state);
-  led_state = 1 - led_state; // toggle
+    board_led_write(led_state);
+    led_state = 1 - led_state; // toggle
+  }
 }
diff --git a/examples/device/usbtmc/src/main.h b/examples/device/usbtmc/src/main.h
new file mode 100644
index 000000000..673247ec7
--- /dev/null
+++ b/examples/device/usbtmc/src/main.h
@@ -0,0 +1,5 @@
+#ifndef MAIN_H
+#define MAIN_H
+void led_indicator_pulse(void);
+
+#endif
diff --git a/examples/device/usbtmc/src/usbtmc_app.c b/examples/device/usbtmc/src/usbtmc_app.c
index 4ec6ad90c..6b72bb360 100644
--- a/examples/device/usbtmc/src/usbtmc_app.c
+++ b/examples/device/usbtmc/src/usbtmc_app.c
@@ -25,6 +25,7 @@
 
 #include <strings.h>
 #include "class/usbtmc/usbtmc_device.h"
+#include "main.h"
 
 #if (USBTMC_CFG_ENABLE_488)
 usbtmc_response_capabilities_488_t const
@@ -39,7 +40,7 @@ usbtmcd_app_capabilities  =
     {
         .listenOnly = 0,
         .talkOnly = 0,
-        .supportsIndicatorPulse = 0
+        .supportsIndicatorPulse = 1
     },
     .bmDevCapabilities = {
         .canEndBulkInOnTermChar = 0
@@ -63,7 +64,7 @@ usbtmcd_app_capabilities  =
 #endif
 };
 
-static const char idn[] = "TinyUSB,ModelNumber,SerialNumber,FirmwareVer";
+static const char idn[] = "TinyUSB,ModelNumber,SerialNumber,FirmwareVer\n";
 static uint8_t status;
 static bool queryReceived = false;
 
@@ -96,7 +97,7 @@ bool usbtmcd_app_msgBulkIn_complete(uint8_t rhport)
   return true;
 }
 
-static uint8_t noQueryMsg[] = "ERR: No query";
+static uint8_t noQueryMsg[] = "ERR: No query\n";
 bool usbtmcd_app_msgBulkIn_request(uint8_t rhport, usbtmc_msg_request_dev_dep_in const * request)
 {
   usbtmc_msg_dev_dep_msg_in_header_t hdr = {
@@ -127,7 +128,7 @@ bool usbtmcd_app_msgBulkIn_request(uint8_t rhport, usbtmc_msg_request_dev_dep_in
 }
 
 // Return status byte, but put the transfer result status code in the rspResult argument.
-uint8_t usbtmcd_app_get_stb(uint8_t rhport, usbtmc_status_enum *rspResult)
+uint8_t usbtmcd_app_get_stb(uint8_t rhport, uint8_t *rspResult)
 {
   (void)rhport;
   *rspResult = USBTMC_STATUS_SUCCESS;
@@ -137,3 +138,7 @@ uint8_t usbtmcd_app_get_stb(uint8_t rhport, usbtmc_status_enum *rspResult)
   return status;
 }
 
+bool usbtmcd_app_indicator_pluse(uint8_t rhport, tusb_control_request_t const * msg)
+{
+  led_indicator_pulse();
+}
diff --git a/src/class/usbtmc/usbtmc_device.c b/src/class/usbtmc/usbtmc_device.c
index 909f8251f..7bc768a58 100644
--- a/src/class/usbtmc/usbtmc_device.c
+++ b/src/class/usbtmc/usbtmc_device.c
@@ -39,17 +39,18 @@
 
 //Limitations (not planned to be implemented):
 // "vendor-specific" commands are not handled
+// Dealing with "termchar" must be handled by the application layer,
+//    though additional error checking is does in this module.
 
 // TODO:
 // USBTMC 3.2.2 error conditions not strictly followed
 // No local lock-out, REN, or GTL.
-// Cannot issue clear.
-// No "capabilities" supported
-// Interrupt-IN endpoint
-// 488 MsgID=Trigger
+// Cannot handle clear.
+// Not all "capabilities" supported
 // Clear message available status byte at the correct time? (488 4.3.1.3)
 // Split transfers
-// No CLEAR_FEATURE/HALT (yet)
+// No CLEAR_FEATURE/HALT no EP (yet)
+// No aborting transfers.
 
 #if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_USBTMC)
 
@@ -156,8 +157,11 @@ void usbtmcd_init(void)
 {
 #if USBTMC_CFG_ENABLE_488
   if(usbtmcd_app_capabilities.bmIntfcCapabilities488.supportsTrigger)
-    TU_ASSERT(usbtmcd_app_msg_trigger != NULL,);
+    TU_ASSERT(&usbtmcd_app_msg_trigger != NULL,);
 #endif
+  if(usbtmcd_app_capabilities.bmIntfcCapabilities.supportsIndicatorPulse)
+    TU_ASSERT(&usbtmcd_app_indicator_pluse != NULL,);
+
 }
 
 bool usbtmcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length)
@@ -400,8 +404,9 @@ bool usbtmcd_control_request(uint8_t rhport, tusb_control_request_t const * requ
     return true;
   // USBTMC Optional Requests
   case USBTMC_bREQUEST_INDICATOR_PULSE: // Optional
-    TU_VERIFY(false);
-    return false;
+    TU_VERIFY(usbtmcd_app_capabilities.bmIntfcCapabilities.supportsIndicatorPulse);
+    TU_VERIFY(usbtmcd_app_indicator_pluse(rhport, request));
+    return true;
 
 #if (USBTMC_CFG_ENABLE_488)
     // USB488 required requests
diff --git a/src/class/usbtmc/usbtmc_device.h b/src/class/usbtmc/usbtmc_device.h
index 1246d11d1..09cda7c67 100644
--- a/src/class/usbtmc/usbtmc_device.h
+++ b/src/class/usbtmc/usbtmc_device.h
@@ -64,8 +64,10 @@ bool usbtmcd_app_msgBulkIn_request(uint8_t rhport, usbtmc_msg_request_dev_dep_in
 
 bool usbtmcd_app_msgBulkIn_complete(uint8_t rhport);
 
+TU_ATTR_WEAK bool usbtmcd_app_indicator_pluse(uint8_t rhport, tusb_control_request_t const * msg);
+
 #if (USBTMC_CFG_ENABLE_488)
-uint8_t usbtmcd_app_get_stb(uint8_t rhport, usbtmc_status_enum *rspResult);
+uint8_t usbtmcd_app_get_stb(uint8_t rhport, uint8_t *rspResult);
 TU_ATTR_WEAK bool usbtmcd_app_msg_trigger(uint8_t rhport, usbtmc_msg_generic_t* msg);
 //TU_ATTR_WEAK bool usbtmcd_app_go_to_local(uint8_t rhport);
 #endif