diff --git a/artiq/frontend/artiq_ddb_template.py b/artiq/frontend/artiq_ddb_template.py
index 239c0ac241..89c062eaa5 100755
--- a/artiq/frontend/artiq_ddb_template.py
+++ b/artiq/frontend/artiq_ddb_template.py
@@ -140,7 +140,7 @@ def process_dio(self, rtio_offset, peripheral, num_channels=8):
             class_names[peripheral["bank_direction_high"]]
         ]
         channel = count(0)
-        board = peripheral["board"].lower() if "board" in peripheral else ""
+        board = peripheral["board"] if "board" in peripheral else ""
         name = [self.get_name("ttl") for _ in range(num_channels)]
         for i in range(num_channels):
             self.gen("""
diff --git a/artiq/frontend/artiq_sinara_tester.py b/artiq/frontend/artiq_sinara_tester.py
index 53ba2b3d12..135af90778 100755
--- a/artiq/frontend/artiq_sinara_tester.py
+++ b/artiq/frontend/artiq_sinara_tester.py
@@ -50,7 +50,7 @@ def build(self):
         self.leds = dict()
         self.ttl_outs = dict()
         self.ttl_ins = dict()
-        self.ttl_lvds_outs = dict()
+        self.ttl_lvds = dict()
         self.ttl_lvds_ins = dict()
         self.urukul_cplds = dict()
         self.urukuls = dict()
@@ -75,12 +75,12 @@ def build(self):
                     dev = self.get_device(name)
                     if "led" in name:  # guess
                         self.leds[name] = dev
-                    elif "board" in desc and desc["board"] == "dio_lvds":
-                        self.ttl_lvds_outs[name] = self.get_device(name)
+                    elif "board" in desc and desc["board"].lower() == "dio_lvds":
+                        self.ttl_lvds[name] = self.get_device(name)
                     else:
                         self.ttl_outs[name] = dev
                 elif (module, cls) == ("artiq.coredevice.ttl", "TTLInOut"):
-                    if "board" in desc and desc["board"] == "dio_lvds":
+                    if "board" in desc and desc["board"].lower() == "dio_lvds":
                         self.ttl_lvds_ins[name] = self.get_device(name)
                     else:
                         self.ttl_ins[name] = self.get_device(name)
@@ -163,7 +163,7 @@ def build(self):
         self.ttl_outs = sorted(self.ttl_outs.items(), key=lambda x: x[1].channel)
         self.ttl_ins = sorted(self.ttl_ins.items(), key=lambda x: x[1].channel)
         self.ttl_lvds_ins = sorted(self.ttl_lvds_ins.items(), key=lambda x: x[1].channel)
-        self.ttl_lvds_outs = sorted(self.ttl_lvds_outs.items(), key=lambda x: x[1].channel)
+        self.ttl_lvds = sorted(self.ttl_lvds.items(), key=lambda x: x[1].channel)
         self.urukuls = sorted(self.urukuls.items(), key=lambda x: (x[1].cpld.bus.channel, x[1].chip_select))
         self.samplers = sorted(self.samplers.items(), key=lambda x: x[1].cnv.channel)
         self.zotinos = sorted(self.zotinos.items(), key=lambda x: x[1].bus.channel)
@@ -268,21 +268,23 @@ def devices_to_string(chunk):
             else:
                 print("FAILED")
 
-    def test_ttl_lvds_outs(self):
+    def test_ttl_lvds(self):
         def lower_bound_of_device_chunk(dev_list, dev_name, N):
             dev_index = next(i for i, v in enumerate(dev_list) if v[0] == dev_name)
             return dev_index - (dev_index % N)
 
         print(f"*** Testing LVDS TTL")
 
-        if len(self.ttl_lvds_ins) == 0:
+        if not self.ttl_lvds_ins:
             print(f"No available input channels for testing. Skipping...")
             return
 
-        ttl_in_index, ttl_out_index = 0, 0
+        ttl_in_index, ttl_out_index = 0, -1
         default_ttl_in_name, _ = self.ttl_lvds_ins[ttl_in_index]
-        default_ttl_out_name, _ = self.ttl_lvds_outs[ttl_out_index]
+        default_ttl_out_name, _ = self.ttl_lvds[ttl_out_index]
 
+        print("LVDS TTL channels are tested in groups of 4.")
+        print("You can choose any channel within the group.")
         ttl_in_name = input(f"TTL device to use as an input (default: {default_ttl_in_name}): ")
         ttl_out_name = input(f"TTL device to use as an output (default: {default_ttl_out_name}): ")
 
@@ -292,18 +294,18 @@ def lower_bound_of_device_chunk(dev_list, dev_name, N):
             ttl_out_name = default_ttl_out_name
 
         ttl_in_index = lower_bound_of_device_chunk(self.ttl_lvds_ins, ttl_in_name, 4)
-        ttl_out_index = lower_bound_of_device_chunk(self.ttl_lvds_outs, ttl_out_name, 4)
+        ttl_out_index = lower_bound_of_device_chunk(self.ttl_lvds, ttl_out_name, 4)
         ttl_in_static_chunk = self.ttl_lvds_ins[ttl_in_index: ttl_in_index + 4]
-        ttl_out_static_chunk = self.ttl_lvds_outs[ttl_out_index: ttl_out_index + 4]
-
-        print("LVDS TTL channels are tested in groups of 4.")
-        print("\nTesting output channels. Keep input group connected in the same slot, and cycle through all outputs.")
+        ttl_out_static_chunk = self.ttl_lvds[ttl_out_index: ttl_out_index + 4]
 
-        for ttl_out_moving_chunk in chunker(self.ttl_lvds_outs, 4):
+        print("\nTesting output channels. Keep input group connected in the same port, and cycle through all outputs.")
+        for ttl_out_moving_chunk in chunker(self.ttl_lvds, 4):
             self.test_lvds_group(ttl_out_moving_chunk, ttl_in_static_chunk)
 
-        print("\nTesting input channels. Keep output group connected in the same slot, and cycle through all inputs.")
+        if len(self.ttl_lvds_ins) == 4:
+            return
 
+        print("\nTesting input channels. Keep output group connected in the same port, and cycle through all inputs.")
         for ttl_in_moving_chunk in chunker(self.ttl_lvds_ins, 4):
             if not ttl_in_moving_chunk == ttl_in_static_chunk:
                 self.test_lvds_group(ttl_out_static_chunk, ttl_in_moving_chunk)