Revision 1.0

Page 14 of 44

nRF24AP2-USB Product Specification

4.2.1

ANT nodes

All ANT networks are built up of nodes. See the ANT node represented in Figure 6. on page 14. A node

can be anything from a simple sensor to a complex, collection unit like a watch or computer. Common to all

nodes is that they contain an ANT engine (nRF24AP2) handling all connectivity to other nodes and a host

processor handling the application features. nRF24AP2 interfaces to the host processor through a serial

interface, and all configuration and control are performed using a simple command library.

Figure 6. The ANT node

4.2.2

ANT channels

nRF24AP2 can establish one or up to eight logic channels, called ANT channels, to other ANT nodes. The

number of ANT channels available depends on the nRF24AP2 variant being used.

Figure 7. ANT nodes and the channel between them

The simplest ANT channel is called an independent channel and consists of two nodes, one acting as

master, the other as slave for this channel. For each ANT channel opened, nRF24AP2 will set up and

manage a synchronous wireless link, exchanging data packets with other ANT nodes at preset time

intervals called channel periods. See Figure 8. on page 15. The master controls the timing of a channel,

that is to say, it will always initiate communication between the nodes. The slave locks on to the timing set

by the master, receives the transmissions from the master and can then (if configured so) send acknowl-

edge and/or data (if any) back to the master.

Host MCU

nRF24AP2

(ANT engine)

Node

Serial interface

Host MCU

nRF24AP2

(ANT engine)

Node 1

Host MCU

nRF24AP2

(ANT engine)

Node 2

Channel A

Master

Slave