Model VP-EC-RDU Modbus RTU LCD Display 4 Line x 20 Character, RS485, LED Indicators and Audible
The VP-EC-RDU Remote Display by VP Process Inc. is the perfect addition to any controls system or project that uses the MODBUS RTU protocol and RS485.
The easy to read 4 line x 20 character display is simply written to by writing the applicable holding registers, along with the status LEDs and Audible. The four user buttons are read and can be programmed for different functions as required by the user's application. Arduino and Raspberry Pi projects can also use the VP-EC-RDU when using the Arduino and Raspberry Pi serial ports as RS485.
An added bonus is the board temperature sensor (10K 3380 Beta Thermisor) that can be displayed and read via it's Holding Register.
- Low Power (9 - 24 VDC typical, max 28 VDC)
- Power Consumption: 20mA @ 24VDC, 11mA @ 12VDC
- LCD Display 4 Line x 20 Character, White Characters, Blue Background (Other colors available upon request)
- 2 Programmable Status LEDs ( Green - Amber - Red )
- Blue Power On Led
- Audible (Programmable)
- 4 User Pushbuttons (Menu, Up, Down, Enter)
- RS485 Interface 1 External RJ45 (Cat5e), 1 Internal RJ45 (Cat5e) , 1 Internal 4 Pt. Terminal Block
- Programmable Baud Rates ( 9600 or 19.2K Baud N81 )
- Easy Front Cover Removal (4 Screws)
- Modbus ID Programmable
- Modbus RTU Protocol
- Compact, Rugged Case
- 4x20 LCD Backlight Programmable Always ON, Timed Off
- Simple Operation Read and Write Modbus Holding Registers
- Enclosure Dimensions 4" x 6" x 1.25"
- Microchip PIC18F Series Processor c/w ICSP connection
- Arduino and Raspberry Pi compatible when using RS485 with Arduino and Raspberry Pi projects
- Temperature Sensor (10K 3380 Beta Thermistor), temperature calculated using a Steinhart-Hart equation.
Two versions of this product are available:
Model: VP-EC-RDU is the complete unit with case, assembled and tested
Model: VP-EC-RDU-PCB is the same except without the case and graphic label.
PCB Dimensions: 5.175" x 3.435"
For OEM's, we will provide a custom graphic label on quantities of 100 or greater. Please contact us for further details.
Modbus Function 16 Write Multiple Holding Registers
The LCD uses both high and low bytes of the Holding registers and displays the ASCII characters as follows:
Holding Register Address - Description
0 to 9 LCD Line 1 (20 Character ASCII String)
10 to 19 LCD Line 2 (20 Character ASCII String)
20 to 29 LCD Line 3 (20 Character ASCII String)
30 to 39 LCD Line 4 (20 Character ASCII String)
40 Status LED 2
41 Status LED 1
42 Audible 0 = OFF, 1 = ON
Status LED States are defined as follows:
GREEN SLOW FLASH 0x11
GREEN FAST FLASH 0x21
AMBER SLOW FLASH 0x12
AMBER FAST FLASH 0x22
RED SLOW FLASH 0x14
RED FAST FLASH 0x24
Download the User Manual
Python Sample Code for the Raspberry Pi 3:
For a more economical approach, look at the new VP-EC-RDU-MINI display