![background image](http://html1.mh-extra.com/html/elpro-technologies/wi-mod-9-d/wi-mod-9-d_user-manual_2396109022.webp)
WI-MOD-9-D
Radio Modem
User Manual v1.9
WI-MOD-9-D
Manual
v 1.9
Page
22
lead-in
system/group addr
data
error check (if configured)
|---------------|-----------------|------------------------------------------|--------------|
30msec
2 bytes
0.5ms per byte
2 bytes
1 ms @19.2Kb
@ 19.2Kb
1ms @ 19.2Kb
If error checking is not configured at the receiving unit, data will start to be output
approximately 1 msec after the system address has been received. If error checking is
configured, data will be output approx 2msec after the end of the message. For example, a
message with 20 bytes of data transmitted at 19200 bits/sec will begin to be output approx
32msec after the data is input, if there is no error checking, or 44msec after the data is input if
error checking is configured.
3.5
Transparent Mode Repeaters
A module can be configured as a transparent mode repeater. In this mode, the module will
operate as a normal transparent mode module, plus it will also re-transmit any radio messages
that it receives. However it will change the group address in the re-transmitted message. The
transparent mode repeater is configured with two group addresses. When it receives a radio
message with one of these group addresses, it will re-transmit the message using the other group
address (assuming that the system address is correct).
One of the group addresses will be its normal or “first” group address. If a transparent mode
repeater receives a message on its first group address, it will output the data on its serial port,
and will also re-transmit the message using its second group address. That is, the re-transmitted
message will now have the second group address. Only WI-MOD-9-D modules configured with
the second group address will accept the re-transmitted message.
If a transparent mode repeater receives a message on its second group address, it will re-transmit
the message on its first group address, but it will
not
output the data on its serial port. Here is an
example :
A
B
C
G ro u p Ad d re s s
F irs t
1
2
3
S e c o n d
2
3
4
S
T
X
Z
R e p e a te rs
Re m o te
M o d u le s
G ro u p Ad d re s s
1
2
4