Update modbus.markdown (home-assistant#4261)

goldminenine · fabaff · commit df0e39561614 · 2017-12-29T09:20:31.000+01:00
Documentation change associated to pull request: home-assistant/core#11238
diff --git a/source/_components/modbus.markdown b/source/_components/modbus.markdown
@@ -30,7 +30,10 @@ modbus:
 
 Configuration variables:
 
-- **type** (*Required*): Type of the connection to Modbus.
+- **type** (*Required*): Type of the connection to Modbus. Possible values are:
+  - *tcp*: Modbus TCP protocol according to "MODBUS Messaging Implementation Guide version 1.0b" provided by Schneider Automation, 
+  - *udp*: Modbus TCP form, but using UDP for transport (removes the overheads required for TCP),
+  - *rtuovertcp*: Modbus RTU message transmitted with a TCP/IP wrapper and sent over a network instead of serial lines.
 - **host** (*Required*): The IP address of your Modbus device, eg. 192.168.1.1.
 - **port** (*Required*): The port for the communication.
 - **timeout** (*Optional*): Timeout for slave response in seconds. (default: 3)
@@ -51,7 +54,7 @@ modbus:
 
 Configuration variables:
 
-- **type** (*Required*): Type of the connection to Modebus.
+- **type** (*Required*): Type of the connection to Modbus.
 - **method** (*Required*): Method of the connection to Modbus.
 - **port** (*Required*): The port where your Modbus device is connected to your Home Assistant host.
 - **baudrate** (*Required*): The speed for the serial connection.
