# DVI7911 Junction Board

Last modified by Michael Sibayan on 2022/05/03 16:48
Export
Office Formats
Export as PDF
Other Formats
Export as HTML

# Overview

The purpose of this board is to combine cabling of five (5) Davis Instruments anemometers into a pair (2) of 8-conductor cables and handle external circuitry required for data acquisition with these devices. Each Davis Instruments anemometer requires an excitation voltage of approximately 3.3 VDC and a pull-up resistor on the relay output of cup anemometer. A simple diagram of the internal circuitry of the Davis Instruments device is shown below:

The normally open single pole single throw (NO-SPST) relay is actually a reed switch that closes for approximately 4ms when the cup anemometer passes the correct position. The potentiometer wiper is controlled by the wind vane. In order to monitor the junction box provides excitation regulation at 3.3VDC (from a 5VDC source), and pull up resistors for the reed switch. Below is the circuit diagram used on the junction board:

# Images of the board, layout, and pin assignments

Pin assignment:

### Plugs 1 through 5

1. N/C
2. +3.3VDC
3. Potentiometer output
4. Reference (Ground)
5. Relay output
6. N/C

### Plug A

1. Device 1 relay output
2. Device 1 potentiometer output
3. Device 2 relay output
4. Device 2 potentiometer output
5. Device 3 relay output
6. Device 3 potentiometer output
7. Device 4 relay output
8. Device 4 potentiometer output

### Plug B

1. Device 5 relay output
2. Device 5 potentiometer output
3. N/C
4. N/C
5. N/C
6. Voltage monitor (output of regulator)
7. +5VDC (supply voltage)
8. Reference (Ground)

0
Tags:
Created by Michael Sibayan on 2022/05/03 16:48

- Attachments (6)
- History

# Quick Links

Biosphere2 Wiki Home

Landscape Evolution Observatory
- Data
- Irrigation
- Instrumentation
- Data-logging & Control
- Protocols & Walkthroughs
- Science Meetings
- Isotope Lab
- Missing Data

Mini LEO

Tropical Rain Forest
- Data-logging

Outside Weather
- Data-Logging
- Weather Underground

Ocean

# Blog Categories

- https://wiki.b2.arizona.edu/xwiki/bin/view/Blog/">All

- Data-logging and Controls (33)
- Experiments (10)
  - bigPERTH_Soil Coring_After First Rainfall Pulse (2)
- Facilities (4)
- Irrigation (16)
- LEO (77)
- Mini LEO (8)
- News (2)
- Ocean (0)
- Other (2)
- Personal (0)
- TRF (0)

# Blog Archive

- 2009 (1)
- 2012 (4)
- 2013 (3)
- 2015 (22)
- 2016 (15)
- 2017 (4)
- 2018 (8)
- 2019 (9)
- 2020 (11)
- 2021 (5)
- 2022 (3)
- 2023 (1)
- 2024 (1)

# Recent Blog Posts

- LEO Irrigation issues

- RO Filter Information

- West bay DVI7911 replacement

- West bay SDI12 power supply replaced

- West bay CSAT3 reinstall

- LEO center 5TM MPS2 sensor array offline

- CSAT3 redeployment

- EX81 flow meters zero reset

- Biweekly rain modification due to power fluctuation

- Rain schedule post CRQ experiment

# Recently Modified

- LEO Irrigation issues
- RO Filter Information
- Profile of Rhiannon Nabours
- Rain schedule post CRQ experiment
- West bay DVI7911 replacement

This wiki is licensed under a Creative Commons 2.0 license
XWiki Enterprise 13.10.5 - Documentation