Use Laurel’s 6-wire data cables CBL03-1 (1 ft) and CBL03-7 (7 ft) to interconnect meters if these lengths fit your application. How fast can I collect data via RS485? Where can I find RS485 pinouts? RS485 is in its design a different interface from RS232. We have open-sourced the serial bus servo control demos and JSON communication interface. For communications, many of their products are equipped with an RS232 or RS485 serial port. Pin 1 and 6 however are reassigned to the A and B lines when the port is used in RS485 mode. For RS232 a crossover cable is used where pin 1 is connected with pin 6 at the other connector, pin 2 with pin 5, etc. This interconnects the transmit and receive signals of both PLCs, and also the handshaking signals DTR and DSR. When the DSR and DTR signals are not used, the two pins can be used for simultaneous RS485 communication.

The two jacks are for RS485 cable in and RS485 cable out. What communication protocols are supported by RS485? Both protocols (or communication languages) are built into the instrument’s firmware and are user selectable. Laureate meters are modular with a middle slot reserved for a communication board, as illustrated in our Laureates Overview web page. These cables allow the dual RJ11 jacks of the RS485 option board of Laureate meters (digital interface ordering option 2) to be daisy chained and to be addressed digitally with no need for a hub. By using two jacks, up to 31 L485 boards can be connected in parallel for daisy chaining using readily available CBL03 data cables with no need for a hub. These cables are specifically designed to transmit data securely between the devices, typically using a multi-wire configuration to carry power, data, and control signals. The document discusses serial and parallel communication, describing that serial communication transmits one data bit at a time while parallel communicates multiple bits simultaneously, with serial being slower but requiring fewer cables. Not more than one breakout board is required per RS485 line.

The solution is provided by the Laureate DIN rail mounted breakout board, which provides two RJ11 jacks with six screw clamp terminals all wired in parallel. The LPC2148 has two UART peripherals (UART0 and UART1) that can be used to connect serial devices like GSM and Bluetooth modules. To set up communications for your meter or counter, see the Serial Communications section of its user manual. See page 7 of the Laurel digital panel meter manual, page 7 of the Laurel counter manual, page 8 of the Laurel scale meter manual, or page 8 of the Custom ASCII protocol manual. When a single RS485 meter or counter is connected to a PC via a cable CBL06, set the PC to 9600 baud. Set the PC to N81 for the Custom ASCII protocol, or to N82 or E81 for the Modbus RTU protocol. In theatre and performance venues, RS-485 networks are used to control lighting and other systems using the DMX512 protocol. If multiple analog input meters or transmitters are digitally addressed in command mode on an RS485 line using the Modbus RTU protocol or the Custom ASCII protocol, the rate becomes about 2 readings per second. A meter will a thermocouple input and set for Modbus RTU needs to set to full duplex even if the wiring and the receiving unit are for half duplex.

A single analog input meter or transmitter can stream readings to a PC at up to 60 readings per second and the Custom ASCII protocol set to continuous (or streaming) model. Then use front panel programming to set the baud rate, protocol, digital address, half or full duplex, and other available parameters. You need to check the resistance of the cat 5 cable but the suggestion to use capacitors at each load and regulate remotely is a must (you'll lose a couple of volts in the cable). The capacitance is close to 12.5 pF/foot but there is a small impedance mismatch (100 ohms for Cat 5, 120 ohms for RS-485). Since RS-485 is a multi-point specification, however, this is not necessary or desirable in many cases. RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. Furthermore, there are plenum-rated RS-485 cables designed for use in building plenum spaces.