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When in RS485 mode, only in 1 and 6 are reassigned. Pin 1 and 6 however are reassigned to the A and B lines when the port is used in RS485 mode. It shouldn’t however be a surprise that the pin assignment on the RJ11 socket on Unitronics PLCs is different from the two systems mentioned above. These ports use an RJ11 socket as physical connector. The RJ11 socket is interesting, because the manufacturer choose to have a symmetrical pin-layout, rs485 cable just as with the MMJ connector on DECconnect systems and the RJ45 jack in the Yost standard. If you ever wanted to connect to device in the same building (e.g. to machinery on production hal) and to you have to go to it to connect your computer. So you can have a reliable, low-cost solution to a heating, ventilation control unit. Can I mix Laureate LT transmitters and meters on the same RS485 line?

How fast can I collect data via RS485? The RJ11 connector can be used for both RS232 and RS485. 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. If handshaking is not necessary, an ordinary 4 wire telephone cable could be used, provided that the pins are cross-connected as shown in the picture below. CAS DataLoggers recently provided the datalogging solution for GSI Grain Storage in Assumption, Illinois, the world's largest manufacturer of steel farm grain bins, commercial storage grain bins and grain silos, as well as grain dryers and material handling systems including grain bin sweeps, spreaders, chain loop systems, commercial bucket elevators and conveyors. 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 RJ11 socket in the Unitronics PLCs provides six signal pins. This MJ20-PRG module clicks in the PLC and provides one RJ11 socket for serial communications with a PC.

The only way to add RS232 capabilities to the Jazz PLCs is by using the MJ20-PRG programming port add-on module. The logger's spacious internal memory supported up to 500k of readings, which could be greatly expanded using an optional SD card. Half duplex has the advantage of only using three wires: ARX/ATX, BRX/BTX and GND. Bus Probes can be configured and tested using our web-based test app (you will need to connect the probes to your PC or Android smartphone via our Web485 board). In all other cases, half duplex and full duplex will work equally well. 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. With Modbus RTU, sending and receiving are never simultaneous, so half duplex is as fast as full duplex. Also enables the analysis of long-term work nodes modbus snmp based on charts and collected the data collected.

Is there an easy way to log data to a PC from multiple instruments on an RS485 bus? Setup is the same when multiple meters are interconnected via cables CBL03, except that all meters now need to be set to a different digital address via their front panel. Then use front panel programming to set the baud rate, protocol, digital address, half or full duplex, and other available parameters. 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. Can I add an RS485 board to a meter later? Boards can be ordered installed with a new meter, and they can also be purchased separately later and be simply plugged in. GSI Grain Storage installed a Novus FieldLogger data acquisition system in a grain storage bin that was repeatedly loaded and unloaded into the storage floor area to measure the separation of the floor sections.