Weather Radar, Collins Type WCP-701 PN 622-5129-020 pinouts
Connector J1

Power +28 VDC M/L (GND)
Integral Backlight +5 VDC P/e
On/Off V/G (pinouts are used for a voltage self test but can be substituted for joystick button functionality)
Predictive Windshear Auto-On/Disable g

ARINC429 (low speed)
<h connect to ARINC429 board INPUT A
<j connect to ARINC429 board INPUT B

The WCP has been interfaced with a Cockpit Concept low speed AIRINC 429 board and ProsimA320/Jeehell FMGS Profile.

Reference
ASM 34-41-01, Rockwell Collins CMM WCP-701 34-45-18