Honeywell MKXXII AIR Data RS-232 Digital Serial BUS Serial Port, +28 VDC Discrete Characteristics

Honeywell

MK XXII EGPWS Installation Manual

E 4.2.9.4 AIR DATA RS-232 DIGITAL SERIAL BUS (SERIAL PORT 2)

One port is provided for use with Air Data computer or Static Pressure Sensor interfaces. This port is common with the Air Data RS-422 port described in Section 0 and can only function as a RS-232 interface or a RS-422 interface but not both.

Pin Assignment (Signal Mnemonic):
Transmit	J2-27	(ADC_TXA)
Receive	J2-11	(ADC_RXA)
Common	J2-28	(GND)

E 4.2.9.5 AIR DATA RS-422 DIGITAL SERIAL BUS (SERIAL PORT 2)

One port is provided for use with Air Data computer or Static Pressure Sensor interfaces. This port is common with the Air Data RS-232 port described in Section 0 and can only function as a RS-232 interface or a RS-422 interface but not both.

Pin Assignment (Signal Mnemonic):
Transmit A leg	J2-27	(ADC_TXA)
Transmit B leg	J2-44	(ADC_TXB)
Receive A leg	J2-11	(ADC_RXA)
Receive B leg	J2-10	(ADC_RXB)

E 4.2.9.6 SCI RANGE RS-422 DIGITAL SERIAL BUS (SERIAL PORT 1)

One port is provided for use with the SCI range bus interfaces. This port is common with the ARINC 429 channel 1 port described in Section 0 and can only function as a RS-422 interface or an ARINC 429 interface but not both.

Pin Assignment (Signal Mnemonic):
Recieve A leg	J2-37	(429/422RX_1A)
Recieve B leg	J2-36	(429/422RX_1B)

E 4.2.10 DISCRETE INPUTS

Discrete signals are intended for remote switching through the aircraft, and are therefore subject to being connected to other signals, and are also subject to transient voltage conditions. For these reasons, the following rules apply to each input, unless otherwise stated.

Each input is capable of withstanding voltage transients of ± 600VDC for 10 ∝s, without damage. The +28 VDC discretes are internally biased via a pull down resistor, and are externally pulled up to +28VDC when active. The characteristics of each +28 VDC discrete input are as follows:

+28 VDC Discrete Characteristics
Quantity	13
Active Voltage Range (Logic True)	> +17 VDC
Inactive Voltage Range (Logic False)	< +4.4 VDC
Diode Isolation	None
Input Impedance	> 95	KΩ
Maximum Fault Current	< 60	∝A
Pin Assignment (Signal Mnemonic):	See specific discrete in Category 13 (28V_DISC_xx)

CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 060-4314-225 REV: C SHEET 174