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A single master can broadcast commands to all the slaves, and can direct commands to an individual slave using its unique address. 2 DyNet over RS232 DyNet message packets can also be sent and received over RS232 networks. For more advanced integration that requires network message filtering or logical processing, the DMNG2322 gateway is ideal. This gateway has advanced features enabling it to receive custom RS232 data strings that can trigger a task or send a Dynet message on the RS485 port. This RS485 board is based on the Analog Devices® ADM2578E Signal and Power Isolated RS-485 Transceiver and provides a full ±15 kV ESD Protection on the Input/Output pins. The Analog Devices ADM2587E is suitable for high-speed transmission rates up to 500 kbps, with integral short circuit protection and thermal shutdown for bus faults. EIA-485 devices may be used in 422 circuits, but EIA-422 may not be used in 485 circuits (because of the lack of an Enable line).

Repeaters may be used to extend the net to any number of devices. ProfiBus defines an RS-485 type bus using repeaters. A number of specifications use EIA-485 as the electrical standard, including SCSI-2, SCSI-3, BitBus, and Profibus. The number of loads, the termination resistance 60 ohms (120 ohms per side), and the required (turn-on) current of the receivers. The driver has the capability of driving 10 receivers of 4k impedance, but the actual number that can be driven depend on the actual input impedance of the receivers, bit rate, wire, stub lengths, biasing and termination of the network. Characters may be lost if the transmit driver is turned off while pending characters are still being transmitted. A logic device may have an "inverting" and/or "non-inverting" output. How long the lines have to be for this to occur depends of the values of the series and parallel resistances (and therefore the frequency being input). Similarly, when establishing the transmit mode, the application software is responsible for ensuring that the RS485 receiver is not disabled until all expected characters have been received.

The master is in charge of designating which receiver is on at any one time. RS422 receivers. One diode between the I/O and Vcc, and another between the I/O and ground. The circuit ground should be connected to chassis ground via a 100 ohm resistor. The drivers and receivers should be connected directly to circuit ground. The laptop is battery powered and has no connection to earth ground. The RF version also transmits via radio at 433MHz (covering longer distances and with less battery consumption thanks to our other special optimizations - there is nothing else on the market for which batteries last this long!) And can transmit to SuperClock, DisplayRX, ControlHUB and RXTXeasy.. These distances can be overcome by running fiber optic cables between the sites and having them connected together via Ethernet gateways. The annex discusses the fact that many applications can handle greater amplitude and timing distortion, and that practical experience has shown that the cable length can be extended to several kilometers at lower data rates. No maximum bus length is given for RS485, but ends up around 1200 meters at 200kbps or 50 meters at 10Mbps. The speed of the system and distance between devices is determined in large amount by the inter-connecting cable.

The device can also be used to send custom RS232 data strings to other third-party devices triggered from Dynet messages. The master can instruct a single slave to go into transmit mode, and then the master can put itself into receive mode, thereby allowing the master to retrieve data from the slave. After the slave transmission is complete, the slave puts itself back into receive mode so that the master can transmit additional commands. TXsoil is a compact and low consumption sensor that can measure and transmit the humidity of the ground WiFi or RF or GSM. The receiver's input impedance is specified in terms of a "unit load" where a unit load is specified as input current in mA at a voltage referenced to ground. The required load is 5 volts / 3.5mA, which results in a load impedance of (around) 1428 ohms. EIA-485 requires a 120 Ohm line impedance (normally Shielded Twisted pair 'STP'), 120W (10%, 1/2 watt) terminations at both ends of the line (at the Receivers).

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