User's Manual

MaxStream, Inc. 24XStream Wireless Module Manual v2.8

Module Address

Module Addresses and Module Address Masks provide another level of addressing among

24XStream modules. Each module in a network can be configured with a 16-bit Module Address

to establish selective communications within a network. This address is set to one of 65535

values using the “DT” command. The default Module Address is 0000H.

All modules with the same Module Address can transmit and receive data among themselves.

Any modules on a network with different Module Addresses will still detect and listen to the data

in order to maintain network synchronization. However, they will not send the data out to their

serial ports if their Module Addresses don’t match the Module Address of the transmitter. (The

Module Address Mask can be used to provide exceptions to this rule as described in the following

section.

Module Address Mask

The Module Address Mask can be used as an additional method to facilitate communication

among modules. The Module Address Mask can also be set to one of 65535 possible values

using the “MK” command. The default value is FFFFH.

All transmitted data packets contain the Module Address of the transmitting module. When a

transmitted packet is received by a module, the Transmitter Module Address (contained in the

packet) is logically “ANDed” (bitwise) with the Receiver Module Address Mask. If the resulting

value matches the Receiver Module Address, or if it matches the Receiver Module Address Mask,

the packet is accepted. Otherwise, the packet is discarded. (When performing this comparison,

any “0” values in the Receiver Module Address Mask are treated as “don’t care” values and are

ignored.)

Packets with a Transmitter Module Address of FFFFH will be received by all modules as shown

below in Figure 10. A Transmitter Module Address that matches the Module Address Mask is

called a Global Address.

Figure 10 – Demonstration of Module Address comparison at receiver. FFFFH logically “ ANDed”

with any Module Address Mask will equal the Module Address Mask.

The following example helps illustrate the manner in which Module Addresses are checked.

Example

Consider a Module (Module A) with Module Address of 00FFH and Module Address Mask

F0F0H as shown in Figure 11 below.