Differences

This shows you the differences between two versions of the page.

--- ocnet:start [2009/08/18 06:53]
theatrus
+++ ocnet:start [2010/08/31 06:13] (current)
theatrus
@@ Line 1: / Line 1: @@
 ====== OpenCoral OCnet ======
-OCnet is now available in two "flavors", OCnet Basic and OCnet Advanced.
+OCnet is a standards-based, easy to implement digital communications channel between various pieces of aquarium control equipment.
-===== OCnet Basic =====
+===== OCnet Overview =====
-OCnet Basic is based upon ModBus/RTU over 2-wire RS-485.
+OCnet is based upon ModBus/RTU over 2-wire RS-485. The connector which is commonly used is the 6P6C (6 position 6 contact) RJ12, with 26 AWG wire in a "reversed" (1 to 6, 6 to 1) configuration between all points. This cable is very inexpensive and very easy to customize to any length required.
+The bus configuration shall be multi-drop capable, allowing you to daisy chain numerous devices.
-===== OCnet Advanced =====
+==== Cable Pinout ====
-OCnet Advanced is built around the [[http://en.wikipedia.org/wiki/Controller-area_network|CANbus]] (Controller Area Network) CAN 2.0A standard. CAN is a very well established bus, commonly used in automotive applications, for communicating amongst the various modules. It features very long bus lengths (above and beyond 100m) and high data rates.
-==== Why CAN? ====
+The pin-out of the cable is as follows:
-CAN was chosen for various reasons over other established industry buses, such as Modbus.
+  * PIN1: +5VDC logic supply (from master only)
+  * PIN2: GND
+  * PIN3: Data - (B)
+  * PIN4: Data + (A)
+  * PIN5: GND
+  * PIN6: +5VDC logic supply (from master only)
-  - Availability of dedicated hardware and software stacks for easy integration.
+==== Serial Parameters ====
-  - Multi-master support: allows clean reporting of exceptions and status, without requiring a single dedicated master.
-  - Faster data rates than most common Modbus implementations.
-  - Robust checksums, data integrity.
-  - Low wire count.
-MODBUS was not chosen due to its single-master nature.
+  * 38,400 baud
+  * 8 bits data
+  * 1 stop bit
+  * 1 start bit
+  * No parity
-===== System Topology =====
-OCnet Advanced devices are on a single line bus. There can be 0 or more "master controllers", which are programmable user interface modules. There can also be 0 or more peripherals or sub-controllers, which can perform both direct and autonomous functions. For instance, a power control strip is a directed module. That is, another device needs to direct the module to change its output. On the other hand, the [[aqtiptop:|TipTop]] allows both directed and autonomous functions - it can both be controlled and also performs actions upon its own local programming.
-==== Higher Level Protocol ====
-More soon.