Company Confidential
31
Raveon Technologies Corp.
1200 through 12FF. Sending data with a destination ID of FF34 will be received by
any modem with a unit ID of 0034 through FF34.
The Address Mask
Only in systems where some modems should only talk to certain other modems,
might you want to change the address mask. Whenever data is received over the
air, the Destination Address of the transmission is logically “ANDed” with the
Address Mask in the receiving modem. This is the
Effective Destination Address
.
The receiving
RF-7800W
also ANDs its own Unit Address with its Address Mask.
The result is the
Effective Unit Address
.
Addressing Examples:
Example 1 (default configuration)
Sending
RF-7800W
Unit Address = 0001
Sending
RF-7800W
Destination Address = 0001
Receiving
RF-7800W
Unit Address = 0001
Receiving Unit’s Address Mask = F000
Result: Unit will receive the data, because the addresses identically match. When the
addresses are identical, the value of the mask is not important.
Notes: This is the default configuration. All units have address 0001, and all modems will talk to
all other modems with address 0001.
Example 2 (a configuration that won’t work)
Sending to Destination Address =
1001
Receiving Unit Address =
0001
Receiving Unit’s Address Mask =
F000
Result: No data will be received, because the address do not match, and the address mask of
FFFF requires that at least the first digit match. .
Example 3 (able to receive data from a sub-group, 1000
– 1999)
Sending to Destination Address =
1236
Receiving
RF-7800W
Unit Address =
1234
Receiving
RF-7800W
Address Mask =
F000
Result: Data will be received. 1236 AND
’ed with F000 is 1000. 1234 ANDed with F000 is
1000. The results of the ANDing perfectly match, and thus the data will be received.
Example 4 (able to receive from a sub-group, 34xx where xx is any two digits)
Sending Destination Address =
3410
Receiving
RF-7800W
’s Unit Address =
3499
Receiving
RF-7800W
’s Address Mask =
FF00
Result: Data will be received. FF00 means first two digits must match, and they do, so the
units will receive each other.
