The Gateway > SmartAck vs. Soft Smart Ack vs. 4BS Teach-in Variation 3

Smart Ack

Smart Ack is a functionality in the EnOcean protocol that allows energy harvesting devices to fall asleep (stop listening on the radio) to preserve energy. Smart Ack turns the conventional request/response dialog (the gateway requests something and the device responds) around and allows the device to wake up at any time, sends a request to the gateway which then answers within a defined short time period before the device falls asleep again.

This functionality is negotiated during the Learn-in and can be seen, whenever a device has the Learn-in procedure "Smart-Ack" when editing a device in the Web Interface.

Smart Ack is handled by the EnOcean Chip (thus in hardware) and from the point of view of the gateway, it receives a command from the API, forwards it to the EnOcean chip which then takes care of delivering the message whenever the device gives notice.

Soft Smart Ack

There are devices, which behave like Smart Ack Devices without using the Smart Ack Specification thus without using the functionality provided by the hardware.

These devices require an answer from the gateway after having sent out a telegram within a certain (mostly 1.000 ms) amount of time. This application layer functionality is provided by the gateway in the way that:

•A command that comes in over the API is answered with a http response code 202 - The telegram will be delivered after the device wakes up and sends something. (Device uses Soft Smart Ack)"

Example Answer:

{

"header" : {

"httpStatus" : 202,

"code" : 1002,

"message" : "will send telegram later",

"gateway" : "DC-GW/EO-IP v0.99.0c",

"timestamp" : "2016-05-27T17:55:27.529+0200"

}

•The telegram is stored by the gateway

•If another (second, third,...) command arrives over the API while a message is still on hold, the gateway will replace the waiting telegram with the last received command (last in -> out)

•When the next telegram from the device arrives, the stored telegram is immediately sent out. The sending out of the telegram is reported over the APIs in the moment of sending.

Known devices requiring Soft Smart Ack:

•Kieback&Peter, MD10-FTL-HE, MD15-FTL-HE

•Micropelt, iTRV

•Soda GmbH, Recent Window Handle

4BS Teach-in Variation 3

4BS Teach-in Variation 3 can be seen as equivalent to the functionality of UTE for the Learn-In process. The device sends out a 4BS Learn-in which is received by the gateway and awaits a 4BS Learn-In back within a certain (mostly 1.000 ms) amount of time.

This application layer functionality is provided by the gateway in the way that when the Gateway receives a 4BS Teach-In for bidirectional profiles, it assumes that it is the Teach-in Variation 3 and replies immediately with an equivalent Teach-In back, thus resulting in fully learned-in devices.

Profiles requiring 4BS Teach-in Variation 3:

•A5-20-XX HVAC Components

•A5-38-08 Central Command Gateway