Signal distribution box
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I am making a signal distribution box, using 24-core 1 square millimeter signal cables. The distribution box has dimensions of 500*400*200, with three 6-way input ports and 24 4-way output ports. There are three types of junction boxes: 1: Switching junction box, which provides 8 DO channels and 16 DI channels, and allows for the configuration of 8 shut-off valves ； An additional 12 analog input channels are provided; Channel 2: an analog input junction box that offers 24 analog inputs, as well as 10 channels for 24V DC power supply. In the case of a mass flow meter, 4 wires are used to connect one analog input and a 24V DC power supply, with the other end connected to the mass flow meter. 3: Analog output junction box, providing 12 analog outputs + 12 analog inputs; since, relatively speaking, analog outputs are used less often, while analog inputs are used more frequently. If a control station has 600 points, and if 2-core cables are used, 600 cables would be required to connect the control room to the workshops; whereas now only 50 24-core cables are needed. This **reduces the number of cables in the control room and cable trays, results in a neater wiring layout, and lowers maintenance costs. It facilitates changes to the workshop processes; when moving instruments, it is sufficient to rewire the 10-20 meters of cable from the junction box to the instrument, **saving labor and cable costs. A distribution box with stainless steel threaded fittings costs only a thousand yuan. The large-end type is available for 24-core cables, at 40 pieces per meter.
Your signal distribution box design is excellent; it effectively reduces the number of cables and the complexity of wiring. It can meet various functional requirements; by using multi-core cables for centralized management and transmission, it not only saves space but also reduces costs and the complexity of maintenance. The design of the three types of junction boxes takes into account the requirements of various industrial control scenarios, with a rational allocation of digital input/output and analog input/output, making them highly suitable for use in large-scale control systems. At the same time, this design also facilitates future process modifications and equipment relocation, enhancing the system’s flexibility and scalability. .
This is a modification based on the existing hardware. Fiber optic? You need slave devices, such as PROFINET slaves; in other words, you’re taking hardware that is essentially part of the control system and moving it to the field. Is such hardware inexpensive?
Next, I will use a microcontroller-based module to collect data from parameters that are not related to safety, such as temperature, pressure, and flow rates in the utility systems, and transmit this data via MODBUS to the Zhejiang University control system. This is because the workshop is equipped only with a 300-series system, and there are no ProfiNET communication modules available. The Modbus serial communication module was made by the microcontroller specialist upstairs; it’s very cheap – you can get 8 channels for just twenty or thirty yuan. The STC microcontroller costs only two or three yuan.
Four 6-mm ports can be installed on the side entrance, with two rows on each of the upper and lower surfaces; each row contains 9 4-mm ports, which are capable of accommodating cables no larger than 12 mm in diameter. In this way, the number of exports reaches 36. There were 12 ports in the previous row; it’s too crowded below in the second row. In this way, 36 outputs are provided; if used solely for analog input, 36 analog input channels can be offered.