diff --git a/artiq/test/coredevice/analyzer.py b/artiq/test/coredevice/analyzer.py
index 81b0d1cfd..fc0650fbe 100644
--- a/artiq/test/coredevice/analyzer.py
+++ b/artiq/test/coredevice/analyzer.py
@@ -1,16 +1,23 @@
 from artiq.language import *
-from artiq.coredevice.analyzer import decode_dump, OutputMessage
+from artiq.coredevice.analyzer import decode_dump, OutputMessage, InputMessage
 from artiq.test.hardware_testbench import ExperimentCase
 
 
 class CreateTTLPulse(EnvExperiment):
     def build(self):
         self.setattr_device("core")
-        self.setattr_device("ttl_out")
+        self.setattr_device("ttl_inout")
 
     @kernel
     def run(self):
-        self.ttl_out.pulse_mu(1000)
+        self.ttl_inout.output()
+        delay_mu(100)
+        with parallel:
+            self.ttl_inout.gate_both_mu(1200)
+            with sequential:
+                delay_mu(100)
+                self.ttl_inout.pulse_mu(1000)
+        self.ttl_inout.count()
 
 
 class AnalyzerTest(ExperimentCase):
@@ -24,9 +31,16 @@ class AnalyzerTest(ExperimentCase):
         exp.run()
 
         dump = decode_dump(comm.get_analyzer_dump())
-        ttl_messages = [msg for msg in dump.messages
-                        if isinstance(msg, OutputMessage)]
-        self.assertEqual(len(ttl_messages), 2)
+        output_messages = [msg for msg in dump.messages
+                           if isinstance(msg, OutputMessage)
+                              and msg.address == 0]
+        self.assertEqual(len(output_messages), 2)
         self.assertEqual(
-            abs(ttl_messages[0].timestamp - ttl_messages[1].timestamp),
+            abs(output_messages[0].timestamp - output_messages[1].timestamp),
             1000)
+        input_messages = [msg for msg in dump.messages
+                          if isinstance(msg, InputMessage)]
+        self.assertEqual(len(input_messages), 2)
+        self.assertAlmostEqual(
+            abs(input_messages[0].timestamp - input_messages[1].timestamp),
+            1000, delta=1)