GE MDS TransNET OEM EL806, Руководство по эксплуатации

Страница: 31 / 110

05-3946A01, Rev. C TransNET OEM Integration Guide 19
When a primary is specified (
XPRI
is 0...31), a radio will always attempt to
find the primary first. If 30 seconds elapses and the primary is not found, then
the radio attempts to synchronize with any non-primary radio in the
XMAP
list.
Once every 30 minutes, if a primary is defined, the radio will check its
synchronization source. If the radio is synchronized to a unit other than the
primary, then the current
RSSI
value is compared to the
XRSSI
value. If
RSSI
is less than
XRSSI
(or if
XRSSI
is
NONE
) the radio will force a
loss-of-synchronization, and hunt for the primary again (as described in the
previous paragraph).
By default, Extensions (and the Master) begin with
XADDR 0
. Synchroniza-
tion qualifiers are set to
XMAP 0
,
XPRI 0
, and
XRSSI NONE
, respectively. This
default configuration allows any radio to hear the Master. When an Extension
is added,
the extended address of the Extension radio must be set to a unique
value . All Remotes that need to hear that extension can specify this either by
designating the extension as the primary (
XPRI
), or by including it in their list
of valid synchronization sources (
XMAP
).
6.2 Establishing a Tail-End Link
A tail-end link can be used to bring an outlying remote site into the rest of an
MAS network.
Figure 4 on Page 5 shows a diagram of this type of system.
A tail-end link is established by connecting an OEM transceiver
“back-to-back” with another unit such as a licensed MDS x710 Series trans-
ceiver. The wiring connections between the two radios must be made as
shown in
Figure 11 . In addition, the
DEVICE CTS KEY
command must be
asserted at the OEM radio.

Figure 11. Data Crossover Cable for Tail-End Links
If required.
RXD
TXD
GND
RTS
3
2
7
4
DCE
DB-25
MDS x710 Series
Remote T
ransceiver
(or de
vice requir
ing k
e
yline)
TXD
RXD
GND
CTS
10
14
5
DCE
16-pin header (J3)
T
ransNET OEM
Remote T
ransceiver
(DEVICE CTS KEY)
16