diff --git a/src/energenie/encoder.py b/src/energenie/encoder.py
index f5897a0..2bc591c 100644
--- a/src/energenie/encoder.py
+++ b/src/energenie/encoder.py
@@ -66,6 +66,8 @@
 
     #TODO: D3210 are the other way round in the message??
     #This is correct as presented by the PDF from Energenie though.
+    #the relay test code above proves that bit position 0 is the on/off command
+    #so the next 3 bits are just like extra address bits
     # Turn switch request into a 4 bit switch command, and add to payload
     # D 3210
     #   0000 UNUSED
@@ -77,24 +79,48 @@
     #   0110 socket 2 off (6)
     #   0111 socket 1 off (7)
     #   1000 UNUSED
-    #   1101 UNUSED
-    #   1110 UNUSED
+    #   1001 UNUSED
+    #   1010 UNUSED
     #   1011 All on       (3)
     #   1100 socket 4 on  (4)
     #   1101 socket 3 on  (5)
     #   1110 socket 2 on  (6)
     #   1111 socket 1 on  (7)
 
+    # Coded as per the (working) C code would be:
+    # b 3210
+    #   0000 UNUSED         0
+    #   0001 UNUSED         1
+    #   0010 socket 4 off   2
+    #   0011 socket 4 on    3
+    #   0100 UNUSED         4
+    #   0101 UNUSED         5
+    #   0110 socket 2 off   6
+    #   0111 socket 2 on    7
+    #   1000 UNUSED         8
+    #   1001 UNUSED         9
+    #   1010 socket 3 off   A
+    #   1100 all off        C
+    #   1101 all on         D
+    #   1110 socket 1 off   E
+    #   1111 socket 1 on    F
+
     if not state: # OFF
         bits = 0x00
     else: # ON
-        bits = 0x08
+        bits = 0x01
 
     if device_address == ALL_SOCKETS:
-        bits |= 0x03 # ALL
-    else:
-        bits += 7-((device_address-1) & 0x03)
-
+        bits |= 0x0C # ALL
+    elif device_address == 1:
+        bits |= 0x0E
+    elif device_address == 2:
+        bits |= 0x06
+    elif device_address == 3:
+        bits |= 0x0A
+    elif device_address == 4:
+        bits |= 0x02
+        
     payload += encode_bits(bits, 4)
     return payload
 
diff --git a/src/legacy.py b/src/legacy.py
index c950c82..45a9ee0 100644
--- a/src/legacy.py
+++ b/src/legacy.py
@@ -91,17 +91,21 @@
         print("waiting")
         time.sleep(2)
 
+
 def legacy_test():
-    ON = encoder.build_relay_msg(True)
-    OFF = encoder.build_relay_msg(False)
+    #TODO: This testing shows that the C code and the specs are out of step
+    #ONE_ON = encoder.build_relay_msg(True)
+    #ONE_OFF = encoder.build_relay_msg(False)
+    ONE_ON  = encoder.build_switch_msg(True, device_address=1)
+    ONE_OFF = encoder.build_switch_msg(False, device_address=1)
 
     while True:
         print("ON")
-        radio.transmit(ON)
+        radio.transmit(ONE_ON)
         time.sleep(1)
     
         print("OFF")
-        radio.transmit(OFF)
+        radio.transmit(ONE_OFF)
         time.sleep(1)