The selection of the right POE switch is not a easy thing, and many switches on the market claim that they can transmit faster, more power and more stability. No matter you're deploying IP cameras, wireless ap, or industrial controllers, choosing an unsuitable switch may occur lack of power, unstable connections, or a costly outage. This article will analyze from different perspectives and help customers to choose the right POE switch.
1.POE Switch: Inflated Technical Specifications in the market
In the industrial switch area, Moxa products is well-known, take its 8-port IEEE 802.3af/at PoE+ standard model of the Moxa EDS-G512E series as an example, let’s look at the standardized way of listing technical specifications. Normally, there are two key parameters to focus on: total unit power consumption and maximum output power of each individual PoE port.
The official datasheet of this model clearly states the following specifications:
EDS-G512E-8PoE-4GSFP: Maximum total PD power consumption of 240W
EDS-G512E-8PoE-4GSFP: Maximum output power of 36W per PoE port
Operating temperature parameters are also specified in detail:
Standard model: -10 ~ 60°C (14 ~ 140°F)
Wide-temperature model: -40 ~ 75°C (-40 ~ 167°F)
From the specification, all parameters are clearly specified in detail. However, some manufacturers obscure their technical specifications. For PoE power ratings, for instance, they only list the maximum power per port while omitting the total power of the whole device. For example, they list like that,
For working temperature parameters, since the Moxa's wide temperature model is labeled - 40 ~ 75°C, some of the manufacturers are directly labeled 80°C to create a better sense of product specification. For example, they list like that,
Ordinary customers do not have a professional test environment such as high or low temperature testing box, it is easy to assume a product delivers superior performance based on better paper specifications, without realizing these figures may well be inflated.All R&D Engineers in the industry know that An 8-port 240W PoE switch that can operate stably in high-temperature environments of 80 to 85°C entails very high hardware costs. Therefore, you should remain skeptical of any PoE switches on the market that boast high specifications at a low price.For Rayin technology’s 201 series POE switch, all listed technical parameters are strictly measured by the actual measurement results from R&D team.
2.The Selection of the POE Chips
The core power supply controller of a PoE switch is the PSE chip, which handles functions including PD detection, power allocation and fault protection. At present, the current industry's main PSE chip is the base unit specification of 4 ports for a poe switch 4 port, which can be combined with a multi-level group to become 24 and 48 port models including a poe switch 16 port. At the same time,according to the integration of power MOS tubes, it is also divided into two kinds of built-in MOS and external MOS, which are different in cost, power limit, heat dissipation and environmental adaptability.
A. Why do PSE chips adopt 4-port and 8-port as their basic unit specifications?
The main reason is that the number of ports in the POE switch, the full name of which is poe switch full form, is widely increased by 4, so the PSE chip is designed for poe switch 4 port and poe switch 8 port, and supports the expansion of devices such as poe switch 24 port.
4 port PSE chip: A single chip supports 4 PoE ports. It features compact size and simple PCB layout, widely applied in 4port and 8 port switches, or used as supplementary units in high port devices.
8 port PSE chip: The mainstream option for multi-port PoE switches. One chip covers 8 PoE ports with better integration and lower cost. Cascading three chips delivers a 24 port design, which serves as the standard configuration for mainstream solutions.
B. What are the differences between integrated MOS and external MOS solutions?
Integrated MOS Solution
The integrated MOS design adopted by poe network switch, integrated control logic circuits and power MOS tube into a single chip for poe powered switch and high-performance poe ++ switch. Its advantages include minimal peripheral circuitry, fewer components, smaller PCB layout footprint, lower overall BOM cost and development barriers, and easier yield control during mass production.
However, it also has notable drawbacks. Restricted by chip package size and heat dissipation capacity, heat accumulates inside the chip, resulting in obvious power derating under high temperature conditions and relatively lower reliability for industrial applications. For this reason, such solutions are generally adopted in commercial grade PoE switches.
External MOS solution
The PSE chip retains only the control logic and the driving circuit, and the power MOS tube is independent of the PCB, which is the standard solution for the high and industrial models. The advantage is that it can choose the low guide resistance, high temperature-resist MOS tube, MOS tube can be independently layout with independent heat dissipation design, the whole machine is more flexible, the long run stability is higher in the wide temperature environment. The disadvantages are the big numbers components, high PCB layout complexity, the cost of BOM and the development threshold are significantly higher than the built-in MOS solution. Therefore, customers must exercise extreme caution during product selection when evaluating PoE switches marketed as industrial grade yet equipped with integrated MOS solutions.
Rayin Technology IS201 series PoE switches adopt the external MOS architecture and undergo rigorous, comprehensive verification tests to ensure reliable device operation in high temperature environments.
3.Conclusion
Rayin Technology PoE switches always feature fully truthful parameter labeling, and we never sacrifice product performance to cut costs.
When purchasing industrial grade switches, do not merely compare unit hardware prices, nor make purchasing decisions based solely on paper specifications. Rayin Technology provides free technical assessment services to help you match the functions required by your project and avoid long term operation and maintenance risks caused by insufficient device performance.
If you need complete product solutions and technical white papers, please visit our official website: www.szrayin.com
