The Laureate P/N LMOD interface board with dual RJ45 jacks allows multiple Laureate meters, counters, timers and remote displays to be connected to the same RS485 line. Dual RJ45 jacks wired in parallel allow multiple instruments to be daisy-chained using data cables or patch cords with RJ45 plugs. In the absence of a computer, a single Laureate meter with an RS485 board can drive multiple Laureate 6-digit remote displays.
Operation can be configured for full-duplex or half-duplex operation using jumpers on the RS485 board. Transmission distances up to one mile 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.
Laurel does not offer RS485 data cables with RJ45 plugs. However, Laurel's alternative P/N L485 RS485 interface board with dual RJ11 jacks is supported by 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, and by our 6-wire data cables or patch cords with RJ11 plugs (P/N CBL03) to daisy chaining meters without use of a hub. The P/N L485 RS485 interface board is recommended for new designs unless specifications call out RJ45 connectors.
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 RS485 RJ11 interface board is similar to the RS485 RJ45 interface board which is the subject of this web page, except that it providess dual RJ11 connectors instead of RJ45 connectors. Both board support the Modbus RTU and Custom ASCII protocols.
The Laureate RS485 RJ11 interface board provides two 6-pin RJ11 jacks, whose pins are wired in parallel. This allows multiple Laureates to be daisy-chained using Laurel's 6-wire CBL03 data cables, with no need for an RS485 hub. It also allows meters with RS485 communications to be connected to a LAN via Laurel's Ethernet-to-RS485 gateway board, or to a host PC via Laurel's USB-to-RS458 gateway board. These Laureate gatewaay boards provide an RJ11 connector, not an RJ45 connector.
The signal levels of the Laureate RS485 boards 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||LMOD|
|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|