The Laureate interface board P/N L485 with dual RJ11 jacks allows multiple Laureate meters, counters, timers and remote displays to be connected to the same RS485 line. The two RJ11 jacks (or connectors), are wired in parallel. One of the jacks can be connected to the USB port of a PC by using our RS485-to-USB converter cable (P/N CBL06) for data I/O or for programming by a PC running our Instrument Setup (IS) software. Having two RJ11 jacks wired in parallel allows multiple instruments to be daisy-chained using readily available 6-wire data cables or patch cords with RJ11 plugs (P/N CBL03). In the absence of a computer, a single Laureate meter with an L485 RS485 board can drive multiple Laureate 6-digit remote displays.
Ideal complements to the P/N L485 RS485 interface board are Laurel's Ethernet-to-RS485 gateway board, which connects a meter network to an Ethernet LAN, and the USB-to-RS485 gateway board, which connects a meter network to a host PC via a standard USB cable. Both gateway boards provide an RJ11 interface to an RS485 network, which can consist of multiple Laureate meters that are easily daisy-chained via CBL03 6-wire data cables.
Operation can be configured for full duplex or half-duplex operation using jumpers on the RS485 board. Transmission distances up to 4,000 ft (1200 meters) are possible. In case of long line lengths, a jumper can be plugged in the RS485 board at the end of the line to insert a 120-ohm termination resistor to minimize signal reflections. The meter, counter or timer should be programmed for full duplex operation, even if the RS485 board is jumpered for half duplex.
Two serial protocols are user-selectable for RS485: Modbus RTU and Custom ASCII. For detailed information on our protocols, please see our communication user manuals.
The Laureate LMOD RS485 interface board is similar to L485 interface board, except that it providess dual RJ45 connectors instead of RJ11 connectors. That board is not supported by readily available cables CBL03 and CBL06 data cables. Therefore, use the L485 board with dual RJ11 connectors as described in this web page, unless design specifications call our RJ45 connectors.
The Laureate RS485 interface board provides two 6-pin RJ11 jacks, whose pins are wired in parallel. This allows multiple Laureates to be daisy-chained using readily available 6-wire CBL03 data cables, with no need for an RS485 hub. The resulting RS485 network can be connected to a LAN via Laurel's Ethernet-to-RS485 gateway board, or to a host PC via Laurel's USB-to-RS458 converter.
The signal levels of the Laureate RS485 board are compliant with the EIA/TIA-485 standard. Devices by different manufacturers can share the same RS485 data line, provided that their connectors are wired appropriately.
|RS485 RJ11 Board Specifications|
|Laurel Part Number||L485|
|Connection||Full duplex (ATX, ARX, BTX, BRX) or|
|half duplex (ATX / ARX, BTX / BRX)|
|Data rates||300, 600, 1200, 2400, 4800, 9600 baud|
|No. of devices on data line||Up to 31 without a repeater, 247 Modbus addresses|
|Connectors||Dual RJ11 jacks for daisy chaining without a hub|
|Line length, max||Up to 5000 feet (1500 meters) at 9600 baud depending on cable|
|Isolation||250V rms working, 2.3 kV rms per 1 min test|
|ESD Protection||15 kV per IEC 1000-4-2|
|EMI Immunity||10 V/m per IEC 1000-4-3|
|EFT Protection||2 kV per IEC 1000-4-4s|
|Short Circuit Protection||Continuous|
|Selectable Protocols||Modbus RTU, Custom Laurel ASCII|
|Modbus RTU Protocol|
|Standards Compliance||Modbus over Serial Line Specification V1.0 (2002)|
|Protocol Type||Master-slave, query-response command mode|
|Data Streaming Mode||Not supported by Modbus specification|
|Data Formats (selectable)||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|
|Main Board Revision Level||Level 5 or above|
|Custom ASCII Protocol|
|Standards Compliance||Laurel proprietary protocol|
|Data Format||No parity, 8 data bits, 1 stop bit|
|Protocol Type||Text string based command mode or continuous data streaming mode|
|Data Streaming Mode||User selectable for up to 60 readings/sec|
|Main Board Revision Level||Any|