Post by khatunejannat on Feb 15, 2024 6:24:06 GMT -5
This question is often asked by students, so I will dedicate this post to this issue.
It is a mistake to think that hardwired logic is an old-fashioned issue; we can also say that it cannot be completely replaced by programmed logic, since field elements, security elements, and, above all, actuators (relays, etc.) will always be needed. contactors, etc.); all of them governed, or not, by programmed logic (PLC), and interconnected within the control cabinet.
On the other hand, the past economic crisis led machine manufacturers to design 'low cost' machinery in order to survive. Therefore, a good part of these machines San Marino Email List are based on hardwired logic. So in many of these machines, the programmed logic part is made up of microcontrollers, or programmable relays, or even microautomata. PLC systems with decentralized periphery are even being used to reduce costs. Manufacturers, observing this trend, began to design control elements with connection to a field bus in order to be part of the network controlled by a single Master PLC (consult the tertiary sector catalogs of the main brands). And they even inserted elements of wired logic of a lower technical level but with identical characteristics.
What criteria can we apply when deciding what percentage of each logic a machine should have?As in all engineering issues, we must try to achieve a balance between performance, the initial budget, objectives, costs and the benefit we will obtain. To specify, we will take into account the complexity of the process to be automated to determine what type of automation is the most appropriate, and then with the budget in hand, decide how we automate.
I will give you an example that I observed some time ago in a well-known brand dedicated to the construction of plastic injection machines:The machines incorporated a system of parameterizable electrical protections and some even had the possibility of connecting to a field bus; Well, these were replaced by simple manual disconnectors with groups of very well calibrated fuses. Some of its multiple functions connected to elements interconnected to a field bus were controlled by command with wired logic and others with programmable relays. The plc was reduced in size and became a specific microcontroller that was developed for that company.
It is a mistake to think that hardwired logic is an old-fashioned issue; we can also say that it cannot be completely replaced by programmed logic, since field elements, security elements, and, above all, actuators (relays, etc.) will always be needed. contactors, etc.); all of them governed, or not, by programmed logic (PLC), and interconnected within the control cabinet.
On the other hand, the past economic crisis led machine manufacturers to design 'low cost' machinery in order to survive. Therefore, a good part of these machines San Marino Email List are based on hardwired logic. So in many of these machines, the programmed logic part is made up of microcontrollers, or programmable relays, or even microautomata. PLC systems with decentralized periphery are even being used to reduce costs. Manufacturers, observing this trend, began to design control elements with connection to a field bus in order to be part of the network controlled by a single Master PLC (consult the tertiary sector catalogs of the main brands). And they even inserted elements of wired logic of a lower technical level but with identical characteristics.
What criteria can we apply when deciding what percentage of each logic a machine should have?As in all engineering issues, we must try to achieve a balance between performance, the initial budget, objectives, costs and the benefit we will obtain. To specify, we will take into account the complexity of the process to be automated to determine what type of automation is the most appropriate, and then with the budget in hand, decide how we automate.
I will give you an example that I observed some time ago in a well-known brand dedicated to the construction of plastic injection machines:The machines incorporated a system of parameterizable electrical protections and some even had the possibility of connecting to a field bus; Well, these were replaced by simple manual disconnectors with groups of very well calibrated fuses. Some of its multiple functions connected to elements interconnected to a field bus were controlled by command with wired logic and others with programmable relays. The plc was reduced in size and became a specific microcontroller that was developed for that company.