diff --git a/packages/modules/smarthome/lambda_/off.py b/packages/modules/smarthome/lambda_/off.py
index cc8274b7f3..526317742f 100644
--- a/packages/modules/smarthome/lambda_/off.py
+++ b/packages/modules/smarthome/lambda_/off.py
@@ -22,7 +22,7 @@
          % (devicenumber, ipadr, uberschuss))
 client = ModbusTcpClient(ipadr, port=502)
 start = 103
-resp = client.read_holding_registers(start, 2)
+resp = client.read_holding_registers(start, 2, unit=1)
 value1 = resp.registers[0]
 all = format(value1, '04x')
 aktpower = int(struct.unpack('>h', codecs.decode(all, 'hex'))[0])
diff --git a/packages/modules/smarthome/lambda_/on.py b/packages/modules/smarthome/lambda_/on.py
index 0b2cc2431b..d74abad74a 100644
--- a/packages/modules/smarthome/lambda_/on.py
+++ b/packages/modules/smarthome/lambda_/on.py
@@ -23,7 +23,7 @@
          % (devicenumber, ipadr, uberschuss))
 client = ModbusTcpClient(ipadr, port=502)
 start = 103
-resp = client.read_holding_registers(start, 2)
+resp = client.read_holding_registers(start, 2, unit=1)
 value1 = resp.registers[0]
 all = format(value1, '04x')
 aktpower = int(struct.unpack('>h', codecs.decode(all, 'hex'))[0])
diff --git a/packages/modules/smarthome/lambda_/watt.py b/packages/modules/smarthome/lambda_/watt.py
index 4d4ed9ceda..a6ad5c641b 100644
--- a/packages/modules/smarthome/lambda_/watt.py
+++ b/packages/modules/smarthome/lambda_/watt.py
@@ -53,7 +53,7 @@
 # aktuelle Leistung lesen
 with ModbusTcpClient(ipadr, port=502) as client:
     start = 103
-    resp = client.read_holding_registers(start, 2)
+    resp = client.read_holding_registers(start, 2, unit=1)
     #
     value1 = resp.registers[0]
     all = format(value1, '04x')
@@ -104,7 +104,7 @@
             builder = BinaryPayloadBuilder(byteorder=Endian.Big, wordorder=Endian.Little)
             builder.add_16bit_int(neupower)
             pay = builder.to_registers()
-            client.write_registers(102, [pay[0]])
+            client.write_registers(102, [pay[0]], unit=1)
             if count1 < 3:
                 log.info(' %d ipadr %s written %6d %#4X' %
                          (devicenumber, ipadr, pay[0], pay[0]))