User's Manual

FIREMASTER IV " MillenniumThree " radio shooting system User’s manual
4.8.3 RS-485
The connection using the RS-485 line, allows the FIREMASTER IV System to
be used WITHOUT the RADIO circuits.
When this operating mode is used, it will be necessary to take into account for
some limitations:
- The maximum number of Remote Units that can be connected together
must be limited to about 15
- The communication by RS-485 serial line is available for the FIRE
mode only. All the programming, testing and modify operations to the
Remote Units, must be still performed using the RADIO link.
- The RS-485 port, when in FIRE mode, is always active: this allows to use
the Firemaster System with a MIXED MODE (RADIO + CABLE).
- If the MIXED mode is used, then the Remote Units must be programmed
in RADIO LINK mode and the antennas must be CONNECTED. Only if
ALL THE REMOTE UNITS have been programmed in "CABLE" mode,
it will be possible to remove the antennas (FOR THE "FIRE" FUNCTION
ONLY).
When the connection by serial RS-485 line is used, all the Units (TX5000 and
RX-48) must be connected each other with a TWO-WIRE TWISTED cable
(available upon request).
In order to simplify the inter-connection between Units, a special PLUG
ADAPTOR is available. The ADAPTOR PLUG can be directly inserted into
the two RS-485 connectors on the front panels of both TX5000 and RX48. The
wiring is made using two spring-loaded binding posts (similar to the LINE
CONNECTORS). The following precautions must be followed for a correct
wiring:
- All RED connectors must be wired together with the RED wire
- All BLACK connectors must be connected together with the WHITE wire
- All ADAPTOR PLUGS (TX5000 and RX48) must be of TYPE “A” i.e.:
WITHOUT the loading resistor
- The ADAPTOR PLUG connected to THE LAST UNIT OF THE CHAIN
(RX48), must be of TYPE “B” i.e.: provided WITH THE 120ohm
TERMINATING RESISTOR.
For other connection details, refer to the diagram below:
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