12 V, i.e. ±7 V on top of the 0-5 V signal range. RS-485 signals are used in a wide range of computer and automation systems. It is interesting to measure the humidity of the ground, but we have also thought about other things; and then we have TXtemp to measure the temperature (one of the uses of TXtemp is in association with SuperClock), and for practically any type of measurement we have TXdata (RS232, RS485 ModBus) - which can be connected to thousands of existing third-party professional RS232 or ModBus meters (and there is something for all needs: temperature and humidity meters, anemometers, voltage meters, energy, light meters, water meters, presence sensors, brightness sensors, soil humidity sensors, etc. ; practically all professional meters are available in ModBus or RS232 standard; and not just meters). We tried to build an organic system so that whoever gets a TXtemp, TXsoil sensor or a bridge for RS232 or ModBus sensors and devices like TXdata can immediately use them without wasting time in configurations (and we also took the opportunity to insert some things into our system some "extra" not foreseen by the standards!). Category 5 (Cat 5, Cat 5e, and Cat 6) cables are the most common Ethernet cables in use today.

These are used in programmable logic controllers and on factory floors. If A is negative with respect to B, the state is binary 1. The reversed polarity (A positive with respect to B) is binary 0. The standard does not assign any logic function to the two states. For an on, space or logic 0 state, the driver's A terminal is positive relative to the B terminal. And even worse, if you have a non opto-isolated device installed on that network, any noise could "drain" to ground through the device itself instead of flowing through the ground terminal at the end of the line, damaging the device in the process! 24 AWG solid wires, which are typically used in Cat 5 cables, can break easily when connected to a screw terminal block, which does not provide any strain relief. In theatre and performance venues, RS-485 networks are used to control lighting and other systems using the DMX512 protocol. By using repeaters very large RS-485 networks can be formed.

RS-485 is also used in building automation as the simple bus wiring and long cable length is ideal for joining remote devices. Multiple receivers may be connected to such a network in a linear, multidrop bus. RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. It does not specify or recommend any communications protocol; Other standards define the protocols for communication over an RS-485 link. Care must be taken that an SC connection, especially over long cable runs, does not result in an attempt to connect disparate grounds together - it is wise to add some current limiting to the SC connection. Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. DH 485 is a proprietary communications protocol used by Allen-Bradley in their line of industrial control units. Although many applications use RS-485 signal levels, the speed, format, and protocol of the data transmission are not specified by RS-485. All communication cabling to be installed in a daisy chain configuration, no T’s are permitted.

Some RS485 devices come with optical isolators installed (also called Galvanic isolation) on the RS485 port, and some don't. Interoperability of even similar devices from different manufacturers is not assured by compliance with the signal levels alone. These manufacturers all agree on the meaning of the standard, and their practice is in widespread use. Works with 4 AA batteries (1.5V, alkaline or Lithium - for outdoor winter use you need to use AA lithium batteries because the alkaline ones suffer from the cold); on request it is also available for working with external 5V power supply. You will need to connect to a WiFi (home, work, laboratory, etc.) through which an MQTT Broker or the Internet is available. In the WiFi settings (as in the figure above illustrating B), choose "WiFi MQTT". 2) right under WiFi settings, instead of WiFi TX to Hub / DisplayRX / RXeasy, choose the other settings and write your server / script URL.

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