Laurel Electronics for Digital Panel Meters, Counters, Timers, Transmitters, Digital Displays

Digital Panel Meters - Counters - Timers
DIN Rail Transmitters - Large Digit Displays

   

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Laureate™ Serial Communication Options

RS-232 interface board for digital panel meter and counter   RS-232 interface board
Single RJ11 connector for point-to-point data communications.
RS-485 interface board for digital panel meter and counter   RS-485 interface board
Dual RJ11 connectors to facilitate daisy-chaining for multipoint communications. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection.
Modbus RS485 interface board for digital panel meter and counter   Modbus RS-485 interface board
Dual RJ45 Modbus connectors to facilitate daisy-chaining for multipoint communications. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection.
CE Mark   UL Mark RoHS Mark

Features

  • Choice of three serial data I/O interface boards:
    1. RS-232 for point-to-point communications.
    2. RS-485 for multipoint communications.
    3. Modbus RS-485 for multipoint communications per Modbus Serial Line Specification V1.0.
  • Allows Laureate meter or counter to:
    1. Output latest value, peak value and alarm status to a computer, PLC or  remote Laureate display.
    2. Serve as a remote display to a computer, PLC or another Laureate.
    3. Be configured (set up) via a computer using Laurel-furnished software.
  • Data rates selectable from 300 to 19,200 bps.
  • Powered by Laureate instrument.
  • Isolated from meter and power grounds.

Description

A serial communication option board allows a Laureate digital panel meter, scale meter, counter or timer to be interfaced to a computer or PLC, or to or other devices with a serial communication port, such as a Laureate 6-digit remote display or a panel-mount printer.

The transmitted data may include the latest reading, peak value, alarm status, or setup information. The data can be displayed, processed and data logged by a computer or PLC. It can also be received by a Laureate 6-digit remote display, which can display the serial data like a meter and also process the serial data to control relays and generate a scaled, isolated 4-20 mA or 0-10V analog output.

For detailed technical information, please download our Serial Communications Manual.

Choice of three Serial Boards

1.  RS-232 Board

Point-to-point communications from a digital panel meter to a computer with RS-232

Point-to-Point Communications via RS-232

RS-233 interface for digital panel meters and counters


The Laureate RS-232 board features a single 6-pin RJ11 jack and is intended for point-to-point communications with a computer, a PLC, or other device with an RS-232 port. Normally there is only one Laureate per RS-232 line. However, multiple 6-digit Laureate remote displays with an RS-232 board can be connected to a single RS-232 line in multidrop fashion and be digitally addressed.

CBL01 cable assembly for Laurel digital panel meters and counters
RS-232 cable for use with Laureate digital panel meters and counters
 
USB cable assembly for Laurel digital panel meters and counters

CBL01 cable assembly.
With DB9 and RJ11 connectors to connect a Laureate to the COM port of a PC.

Combined CBL01 and CBL02 cable assembly.
With USB and RJ11 connectors to connect a Laureate to the USB port of a PC.

 
 
Plugging into the Laureate is the RJ11 connector of a common 6-wire telephone extension cable. Plugging into the COM port of a PC is custom-wired DB9 to RJ11 adapter, which accepts the other end of the telephone extension cable. The DB9-to-RJ11 cable assembly is sold by Laurel as Part No. CBL01. Laurel also sells a USB-to-DB9 adapter a Part No. CBL02. A combined CBL01 and CBL02 cable assembly allows a Laureate to be connected to the USB port of a PC.

The RS-232 request-to-send line (RTS) can be set to a latched mode, where a single reading is transmitted when the line is taken high momentarily. This mode allows a single data transfer to be commanded by another device.

2.  RS-485 Board

The Laureate RS-485 board allows multiple Laureates plus non-Laureate devices to be connected to the same RS-485 line in parallel, multidrop fashion. The RS-485 board provides for up to 31 digital addresses, so that multiple Laureates can be addressed and transmit readings on the same data line. The use of RS-485 lines optimizes utilization of computer ports and simplifies plant wiring. In the absence of a computer, a single Laureate device with an RS-485 board can drive multiple Laureate 6-digit remote displays.

Transmission distances up to one mile are possible. In case of long line lengths, the RS-485 board at the end of the line can be terminated by a jumper-selectable 120-ohm resistor to minimize signal reflections. A full duplex mode with separate wire pairs for transmit and receive is selectable, as well as a half duplex mode with shared transmit and receive wires. For details, please see our Serial Communications Manual.
  

RS485 multidrop communications for Laure digital panel meters and counters

RS-485 multidrop communications

RS-485 interface for Laurel digital panel meters and counters

  
The Laureate RS-485 board provides two 6-pin RJ11 jacks, whose corresponding pins are wired in parallel. This allows multiple Laureates to be daisy-chained with no need for an RS-485 hub.

The signal levels of the Laureate RS-485 board are fully compliant with the EIA/TIA-485 standard. Devices by different manufacturers can share the same RS-485 data line, provided that their connectors are wired appropriately. The Laureate RS-485 board can be used with Modbus; however, the connectors will not be compliant with the Modbus standard.

3.  Modbus RS-485 Board

The Laureate Modbus RS-485 board offers all of the benefits of the Laureate RS-485 board and is fully compliant with the Modbus over Serial Line Specification V1.0 (2002). This includes RJ45 connectors and 2-wire or 4-wire operation (jumper selectable). A benefit of Modbus is that up to 32 devices by different manufacturers can share the same RS-485 data line, be connected using similarly-wired RJ45 connectors, and be addressed using the same protocol.

A computer is required in a Modbus system. The Modbus Serial Line protocol is a master-slave protocol, where a master node (computer) issues commands to slave nodes (peripheral devices) on the bus and processes responses.

The Laureate Modbus RS-485 board features two 8-pin RJ45 jacks wired in parallel, one of which is equipped with two indicator LEDs. The Modbus protocol is implemented by the microcomputer in the Laureate main board and is compliant with the Modbus RTU or ASCII transmission modes.

Hardware Specifications

RS-232 Board
Connection
Data Rates
No. of devices on RS-232 line
Connector
Standards Compliance

RX, TX, GND, RTS (optional)
300, 600, 1200, 2400, 4800, 9600, 19200 bps
1 (point-to-point)
Single RJ11 jack
EIA/TIA-232

RS-485 Board
Modes
Data Rates
No. devices on RS-485 line
Connectors
Standards Compliance

Full duplex (4-wire) or half duplex (2-wire)
300, 600, 1200, 2400, 4800, 9600, 19200 bps
31 max
Two RJ11 jacks wired in parallel for daisy-chaining
EIA/TIA-485

RS-485 Modbus Board
Modes
Data Rates
No. devices on RS-485 line
No. of digital addresses
Connectors
Standards Compliance

Full duplex (4-wire) or half duplex (2-wire)
300, 600, 1200, 2400, 4800, 9600, 19200 bps
32 max
247 max
Two RJ45 jacks wired in parallel for daisy-chaining
Modbus over Serial Line Specification V1.0 (2002)

Electrical specs applicable to all three boards
ESD Protection
EMI Immunity
EFT Protection
Short Circuit Protection
15 kV per IEC 1000-4-2
10 V/m per IEC 1000-4-3
2 kV per IEC 1000-4-4
Continuous

Protocol Specifications
(Implemented by meter main board)

Laurel ASCII
Data Format
Protocol
Applicable boards
Main Board Revision Level

No parity, 8 data bits, 1 stop bit
Laurel Laurel ASCII
RS-232, RS-485, Modbus-RS-485
Any

Modbus RTU
Standards Compliance
Data Formats (selectable)
 
 
Applicable Boards
Main Board Revision Level

Modbus over Serial Line Specification V1.0 (2002)
1.  No parity, 8 data bits, 2 stop bits
2.  Odd parity, 8 data bits, 1 stop bit
3.  Even parity, 8 data bits, 1 stop bit
RS-232, RS-485, Modbus RS-485
Level 5 or above

Modbus ASCII
Standards Compliance
Data Formats (selectable)
 
 
Applicable Boards
Main Board Revision Level

Modbus over Serial Line Specification V1.0 (2002)
1.  No parity, 7 data bits, 2 stop bits
2.  Odd parity, 7 data bits, 1 stop bit
3.  Even parity, 7 data bits, 1 stop bit
RS-232, RS-485, Modbus RS-485
Level 5 or above

  

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Laurel Electronics, Inc.
Industrial Instrumentation & Displays
3183-G Airway Avenue
Costa Mesa, CA 92626, USA
Phone: (714) 434-6131
Fax:
     (714) 434-3766

  
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