We all know that the controller of the constant temperature and humidity chamber is PLC programmable. The input and output of the PLC are physically separated from each other, and are realized by running the program stored in its memory. Its entry and exit are related, not by physical process, not by wiring; but by information process, by soft logic. It works on the basis of making good use of information.
Unlike matter and energy, information has its own laws. Information is easy to process, easy to transmit, easy to store, the information can be reused, and so on. It is precisely because of these characteristics of information that the basic characteristics of PLC are determined.
PLC programming is very convenient: although there are no actual relays, time relays, and counters in the PLC, these devices actually exist through the program (software) and system memory. The number is unimaginable for relay control systems. Even a small PLC can have thousands of internal relays, and hundreds of time relays and counts. Also, the contacts of these relays can be used an unlimited number of times. There are so many internal logic devices in PLC that users do not feel any limitation when using them.
First of all, we should understand the performance and purpose of the constant temperature and humidity chamber. The constant temperature and humidity chamber is the main equipment for the temperature and humidity test. Through the scientific operation test of the equipment, the temperature and humidity test is carried out on the test object. Generally speaking, it is tested under a specific temperature and humidity environment. Using constant temperature and humidity chamber can effectively detect product quality and safety performance.
When using the programmable constant temperature and humidity chamber, some users who are in contact with the device for the first time will wonder, what are the specific meanings and channels of temperature and humidity programming, and what convenient help will it bring to the experiment? Today we will explain it through practical operation cases.
For example, the customer is testing PCBA products. The test conditions are set at a high temperature of 50°C for 7 hours, at -30°C for 6 hours, and run at a high temperature of 80°C and a humidity of 85% for 2 hours. If the continuous running test is achieved.
To meet the above-mentioned multiple test requirements, and to conduct the test without interruption, the temperature and humidity program can be programmed on the controller of the constant temperature and humidity chamber before the start of the test run. The test chamber will perform precise tests according to the test procedure.
Now many constant temperature and humidity chambers have realized the function of network operation, and all kinds of temperature and humidity programming can be edited on the mobile phone or computer, which more conveniently releases the limitation of space and time.
The PLC programming in the constant temperature and humidity chamber also has abundant external devices, which can establish a friendly human-machine interface for information exchange. Program can be input, data can be input, program can be read, data can be read. And reading and writing can be carried out on the screen with pictures and texts. After the data is read, it can be dumped and printed. Data entry can be keyed, card readable, etc.
PLC programming also has a communication interface, which can be connected or networked with a computer to exchange information with the computer. It can also be networked by itself to form a larger and wider control system that a single machine cannot have. PLC programming also has a powerful self-test function for self-diagnosis. The results are automatically recorded. This adds transparency and convenience to its maintenance.