Aeon Wiring Conventions
Aeon has adopted the following conventions for internal chassis wiring and cable construction.
On devices designed by Aeon, pin 1 of a connector is used for a power reference voltage. This reference voltage is variously designated on different devices as ground ("GND"), common ("COM"), return ("RTN"), neutral ("N"), or similar terms, often in combination with other descriptive words or abbreviations like power, power supply, DC, AC, mains, or specific voltages, e.g., "PS COM" or "±15 VDC RTN." In addition to pin 1, other pins may also be connected to the same reference voltage, for example, as may be needed to safely carry a current greater than the capacity of a single pin.
SPECIAL NOTE:
The device power reference voltage is NEVER the green or green/yellow "safety ground" wire that is often provided on AC-powered equipment. It is unfortunately common practice in electrical and electronic work to refer carelessly to either "safety ground" or "reference voltage" simply as "ground." This lazy practice can lead to dangerous confusion.
On AC-powered equipment, the reference voltage, if it exists, is provided by a neutral conductor, NOT safety ground. The neutral conductor is intended to carry the balance current required by the mains "line" conductors.
Safety ground NEVER conveys a current in normal operation. It must only be connected to equipment frames, junction boxes and other physical wiring barriers. The singular purpose of the safety ground wire is to provide a short circuit in the event of a wiring fault or equipment failure. The short circuit will then trip a protection device, such as a fuse or circuit-breaker, which interrupts the circuit, preventing the equipment frame from reaching a dangerous voltage.
Device Cabling
3-pin CPW servo (command pulse width control)
1: GND, brown
2: +5V, red
3: CMD, orange
4-pin RS232 servo (serial communications control)
at servo end
1: GND, brown
2: +5V, red
3: RX/TXD, orange
4: TX/RXD, yellow
at controller end
1: GND, brown
2: +5V, red
3: NC, no connection
4: RX/TXD, orange
5: TX/RXD, yellow
+5V (power for device controllers, e.g., heater controllers, switchbanks, etc.)
1: GND, black
2: +5V, white
+5V mains detect (DAQ-interface connection)
1: GND, black
2: NC, no connection
3: signal (+5V), white
NOTE: DAQ conditioning circuit should be configured with a 10k series resistor
+5V devices with signal
Flat cable
1: GND, black
2: +5V, white
3: signal, gray
NOTE: Re-arrange the conductors at the device end of the cable if necessary
E.g., if the device's signal pin is between its +5V and GND pins, then when inserting the pins into the housing that will connect to the device, put the pin that has the gray wire into the middle position.
Round cable
1: GND, black
2: +5V, red
3: signal, white
Cat5 cable
1: GND, orange/white
2: +5V, orange
3: signal, blue
+5V devices with signal & signal return
Flat cable
1: GND, black
2: +5V, white
3: signal, gray
4: signal return, violet
Round cable
1: GND, black
2: +5V, red
3: signal, white
4: signal return, green
Cat5 cable
1: GND, orange/white
2: +5V, orange
3: signal, blue
4: signal return, blue/white
+15V
1: GND, black
2: +15V, brown
+15V devices with signal
Flat cable
1: GND, black
2: +15V, brown
3: signal, red
Round cable
1: GND, black
2: +5V, red
3: signal, white
Cat5 cable
1: GND, brown/white
2: +15V, brown
3: signal, blue
+15V devices with signal & signal return
Flat cable
1: GND, black
2: +15V, brown
3: signal, red
4: signal return, orange
Round cable
1: GND, black
2: +15V, red
3: signal, white
4: signal return, green
Cat5 cable
1: GND, brown/white
2: +15V, brown
3: signal, blue
4: signal return, blue/white
±15V devices with signal & signal return (DAQ end of cable)
Flat cable
1: GND, black
2: +15V, brown
3: signal, red
4: signal return, orange
5: -15V, yellow (connect to -15V bus strip)
Round cable
1: GND, black
2: +15V, red
3: signal, white
4: signal return, green
5: -15V, brown
Cat5 cable
1: GND, brown/white
2: +15V, brown
3: signal, blue
4: signal return, blue/white
5: -15V, green
(6: -15V return, green/white: also tie to GND)
Mains colors
Safety ground is always green, green/yellow, or bare conductor.
Neutral is preferred to be white or gray, but will always be blue if and only if Line is brown. The latter occurs on equipment or cabling that Aeon purchases pre-assembled.
Line is always brown for single-phase power when Neutral is blue. Otherwise black is preferred for Line when Neutral is white and violet is preferred for Line when Neutral is gray. Red is preferred for Line 2 (L2), and blue is preferred for Line 3 (L3).
120 VAC (power to furnaces, solenoids, etc)
Flat cable
1: neutral, gray
2: line (hot), violet
NOTE: Never use white+black flat cable for 120 VAC power
(white+black flat cable is reserved for 5 VDC with GND)
120 VAC (power cords)
1: neutral, blue
2: line (hot), brown
3: safety ground, green with yellow stripe (omitted on some devices)
OR
1: neutral, white
2: line (hot), black
3: safety ground, green (omitted on some devices)
NOTE: Safety ground NEVER conveys a current in normal operation. It must only be connected to equipment frames, junction boxes and other physical wiring barriers.
NOTE: Never use white+black flat cable for 120 VAC power
(white+black flat cable is reserved for 5 VDC with GND)
RS232
1: GND, green
2: RX/TXD, blue
3: TX/RXD, violet
GRT @ DCE / host / USB adapter: blue = RX, violet = TX
GTR @ DTE / MCU / peripheral device: blue = TXD, violet = RXD
~~~swap TXD/RXD if needed on non-Aeon devices
MCU DBG connector
1: GND, black
2: 3V3, white
3: -RST, gray
4: DBG, violet
RJ-45 connector (use the T568B wiring convention)
1: orange/white
2: orange
3: green/white
4: blue
5: blue/white
6: green
7: brown/white
8: brown
USB
1: GND, black
2: +5V, red
3: Data (+), white
4: Data (-), green
