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). Large phone cables have solid with white stripes, and solid. One was mostly blue with a white stripe and the other was white with a blue stripe. In order to avoid errors when many devices are connected, cables of the same colour should be used for all the connections to the terminals A and cables of the same colour should be used for all the connections to the terminals B of the various devices (e.g. white for A and blue for B). I'm mostly used to ethernet with a pair consisting of completely solid and white with a stripe.

The shielding may be braided (be formed by a mesh of thin conducting wires) or be a foil (consisting of a sheet of metal wound around the conductors): the two types are equivalent. For example, Belden 3105A cable can be specified, but different types of cable with equivalent characteristics can be used. Each serial port can be configured for the RS232 or RS485 protocol, and runs at standard baud rates up to 115,200 bits per second. That places a 120 Ω resistor across the RS485 differential line at the driver chip. End of line termination resistor (120 ohm 1/4 watt) to be installed at both ends of network. RC termination - In some applications requiring low power you may not want to load the line with 120 Ω resistors at each end. If the total length of the main cable is less than 50 m termination resistances can be avoided at the ends of the main cable. The main cable must be no longer than 700 m! Longer branches could cause signal reflections and generate disturbances and consequent errors in the reception of data.

The branches must be no longer than 1200 m! The RS485 system used for Modbus communication provides a main cable (Bus or backbone), to which all the devices have to be connected with branches (also known as stubs) that are as short as possible. This distance does not include the branches (which must nevertheless be short). Both the local and remote UARTs must be configured for the same baud rate. Finally, for master devices, the SPR1 and SPR0 bits determine the baud rate at which data is exchanged. Regardless of the network, however, there are only four signals used: SCK provides a synchronized clock, MOSI and MISO signals are used for data transmission and reception, and /SS configures the QScreen as a master or slave device. In order to increase the extent of the Modbus network, repeaters can be used; and signal amplifying and regenerating devices provided with two communication ports that transfer to each what they receive from the other. When the QScreen controls the network, it is referred to as a "master"; otherwise, it is a "slave".

The maximum number of devices that can be connected to a main cable is 32, including the Master. Maximum length is 4000 ft. 4000 FT. 4000 FT. To ensure that no two devices drive the network at the same time, it is necessary that each slave device be able to disable it’s own RS-485 data transmitter. To ensure that no two devices drive the network at the same time, it is necessary that each slave device be able to disable its own RS485 data transmitter. In a finished instrument, either or both channels can be used to communicate with other serial devices, or with other computers and/or terminals using RS232 or RS485. If on the other hand each terminal can accept only a single cable, a proper branch must be created using three auxiliary terminals for each instrument to be connected. The QScreen Controller combines an embedded computer based on the 68HC11 microcontroller with a touch panel and LCD (liquid crystal display) graphic user interface (GUI) that is ideal for instrument control and automation.

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