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By default, all 720 series key pads come with a standard set of commands which can be used to integrate with existing applications or used to build the metal keypad into new application developments. One of the key advantages also is that RS-485 can drive data a long distance. What it does is that's after sensing the temperature in the room and yet when you're making adjustment to the thermostat, it actually sends the data to the controller, which could be controlling that, the temperature, turning on and off the AC to heat or cool the room up. SMTP - the units can be ordered with the firmware option that sends SMTP messages to a central 'mail server'as an alternative means of integration. It basically goes to a remote PC that has all the pricing information and it sends the data back to you. It can transfer as well as process the data. The rubber buttons offer limited liquid resistance while the wall mount unit can be for indoor use as the 720 SM, shown below or, mounted in a weather resistant enclosure - 720 SMO. The end resistance must be used only at the ends of the main cable.

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. Unlike what happens in many energy distribution systems, the manner in which the devices are connected in parallel is important. Each device has a communication port with two terminals, which are indicated for the sake of convenience as A and B. In these two terminals the communication cable is connected so that all the devices that take part in the communication are connected in parallel. 1. RS232 - Can accept local power or can be cabled to run powered from port. Computer is connected to the converter rs232 rs422 ATC - 105. Converter is also connected to external power, supporting RS485 port. So that's how converter rs485 being used. The cabling of the industrial communication systems (Modbus RS485) is different in some ways from the cabling used for power cabling and the electrician may experience some difficulties if he is not an expert in Modbus communication networks. One of the main reasons why this standard is used it's because wireless rs485 is able to send data a long distance.

RS-485 can send data 1200 meters on cable. Longer branches could cause signal reflections and generate disturbances and consequent errors in the reception of data. 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. Henceforth, we shall consider Slave devices to be measuring instruments with serial communication, even if the cabling is similar for all Modbus devices. This makes it easier to identify cabling errors. 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). The maximum number of devices that can be connected to a main cable is 32, including the Master. Using a repeater, the main cable is divided into different segments, each of which can be up to 700 m in length and connect 32 devices (this number includes the repeaters). 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.

For example, Belden 3105A cable can be specified, but different types of cable with equivalent characteristics can be used. 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. So you can have a reliable, low-cost solution to a heating, ventilation control unit. The RS-485 application in heating, ventilation, air-conditioning unit. If you're sitting in the office right now, and you look to see your thermostat, there's usually RS-485 transceivers connecting that from there to basically the control unit in the building. And RS - 2322 right now, rs485 cable the fastest transceivers right now are 1 megabit. The fastest RS-485 transceivers out there right now are running about 50 megabits. You're talking about at least 10 megabits for the slow ones. So you'll need to really have a high-end PC at each terminal to actually store prices. When you scan the bar code, the information actually gets sent on a 485 transceiver through a long cable to a PC somewhere within the store.