Length of ATC
➤
Cable Runs
The resistance of the cable and the voltage of the power supply to the ATC
determine the maximum cable length. The ATC requires a minimum of
8VDC at the ATC. The PX-700 supplies 10VDC from the RS-485 bus. This
means that up to 2 volts can be dropped due to the resistance of the cable. If
the ATC is powered from a PX-700 and your cable has a nominal resistance
of no more than 26
Ω
/1,000 ft, the cable run should be no more than
approximately 250 feet from the ATC to the ATC RS-232 Interface Board.
If you require a cable run of more than 250 feet, you must either use CAT
5 cable with a resistance of less than 26
Ω
/1,000 ft, or use an AC to DC
adapter that provides a voltage higher than 10VDC. If the ATC is powered
from a 12VDC AC to DC adapter and your cable has a nominal resistance
of no more than 26
Ω
/1,000 ft, the cable run should be no more than
approximately 500 feet from the Interface Board.
If your Cat 5 cable has a resistance other than 26
Ω
/1,000 ft, use the formula
below to figure the maximum length of your cable run or to determine the
appropriate supply voltage for a specific cable length.
Supply Voltage (from PX-700 or adapter) – 8
X (length of cable run) = ___________________________________________ x 1000
.3 x (
Ω
/ft rating of cable)
Four-Conductor
➤
Wiring
If you have already run 4-conductor cable to the ATC location, you have two
choices. You can replace the 4-conductor with Cat 5 and connect the ATC as
described above, or you can install the ATC with the 4-conductor cable.
NOTE:
If you choose to use only 4-conductor cable, you cannot use the RS-232
port (D connector) at the ATC RS-232 Interface board. The ATC will work as
a touch screen with all menus, but you will not be able to use it to control other
systems, nor will you be able to program it after it is installed from the Interface
Board. The ATC must be programmed
prior to
installation.
At the ATC Touchscreen Controller
1. Make a pigtail with a short length of Cat 5 and an RJ-45 8 pin
connector, wired as described above.
2. Splice this to the 4-conductor cable, connecting only power (pin 3),
ground (pin 6) and RS-485 + /data 1 (pin 5) and RS-485 – /data 2
(pin 4).
3. Connect to rear of ATC.
PHYSICAL INSTALLATION
3.6