User`s guide

Installing the DX LCD Display 3-15
5. If required, wire the alarm contacts (Pins 94-96) to the external
annunciation device (alarm horn). The circuit voltage must not
exceed 35 VAC/VDC.
Note: The alarm contacts are provided only on the DX LCD
Display, Version 3 (DT-9100-8104).
6. The VDC supply voltage already available at the DX controller
can power the DX LCD Display. Wire a supply voltage cable to
Pins 91-93, using the 24 VAC pin assignments shown in Figure
3-11.
Extending the Serial Cable with Line Drivers
Note: You can extend the RS-232 serial cable maximum distance
of 15 meters (50 feet) by using line drivers or leased line
modems. We recommend the ME800A-R2 Short-Haul
modem from the Black Box Company. The maximum
distance allowed between the two modems is 3.2 km
(2 miles). If you use shielded cable, the distance is reduced
to 1.1 km (0.7 miles).
To connect the two modems:
1. Use 4-wire 0.6…0.8 mm (24…22 AWG) unshielded twisted pair
telephone cable to wire the short-haul modems so Transmit +
(TX+) on one modem is wired to Receive + (RX+) on the other
modem and Transmit - (TX-) is wired to Receive - (RX-).
A ground connection is optional. See Figure 3-12.
(Transmit +) TX+
(Transmit -) TX-(Transmit -) TX-
(Receive +) RX+
(Receive -) RX-
(Transmit -) TX-
(Transmit +) TX+
(Receive -) RX-
(Receive +) RX+
Modem 1
Modem 2
DTMODEM
}
Pair 2
}
Pair 1
Figure 3-12: Modem Wiring
2. Using the cable provided with the modem, connect the cable’s
9-pin connector to the RS-232 serial port socket at the front of the
DX controller.
3. Plug cable’s 25-pin connector into Modem 1. See Figure 3-14.