Regarding the new project DCS system

Choose early; the sooner, the more proactive you can be

1. The DCS system is generally determined during the initial design phase of a project, as the choice of DCS affects various aspects such as the overall design scheme, instrument selection, wiring, and system integration. If the decision is made only at the final stage of instrument design, it may require significant adjustments to the previous designs. 2. When selecting a DCS system, it should be taken into account that the ECS700 may offer more modern technology, better compatibility, and a longer period of technical support compared to the JX300XP, which is advantageous for future expansions and technological upgrades. If there are not many measurement points in a project and the budget permits, choosing a more advanced system (ECS700) is usually a better decision. 3. The advantage of manufacturers of DCS systems procuring instruments in a centralized manner is that it ensures compatibility between the instruments and the system, thereby reducing integration risks ； More unified technical support and services may be available ； Sometimes, you can also enjoy better prices. Disadvantages may include fewer options, and the price may not be as competitive as when purchasing directly from the manufacturer. If you contact the manufacturer directly, you may get a better price, but you will have to take on more coordination and integration tasks yourself. .

Compared to contacting manufacturers directly, the advantage of having DCS manufacturers handle the purchases centrally is: 1. Lower prices； 2. Higher compatibility between instruments and DCS performance ； 3. The interface is simpler (in case of problems, one only needs to contact DCS) ； 4. The spare parts can be configured more simply (in case of issues, contact the DCS manufacturer for coordination) ； Disadvantages: 1. It is tied to the DCS manufacturer, resulting in limited options for future modifications, expansions, or upgrades ； 2. The advantages for the purchasing department have decreased.

I have used Honeywell’s MACS4 FM and MACS6 K series; it is said that MACS7 or 6.7 is currently in development. For central control systems, I have only used SIS and not DCS. Personally, I think they are all pretty good, each with its own advantages and disadvantages. Currently, electronic wiring technology is being promoted across the country; this involves placing control cabinets on-site with optical fibers connecting them to the central control room. It’s worth exploring this option – by coordinating well with the design team, it can save a significant amount of money in terms of cable materials and installation costs.

We are currently conducting tenders for instruments, valves, DCS, and SIS for our new project. Currently, it is these two companies mentioned by the poster that are bidding. 1. It is recommended not to use the JX300XP; it is the oldest system available for central control, its cards do not support hot swapping, and its functions are relatively basic. 2. We adopt a turnkey approach, meaning that the party B is responsible for purchasing all the instruments, valves, and automation systems. They have access to channels that make purchasing easier, but to be honest the prices are similar to those if you buy it directly, or even higher – those who understand know what I mean. If you buy it on your own, you need to inquire about the price, and since the quantity is small, many major brands may ignore you. The biggest advantage of a general contractor is that it saves hassle.

The only advantage is that it saves one trouble. The price is generally much higher than when purchasing directly. I sell imported instruments, and I have worked with Zhejiang University Zhongkong before. That is, when there’s no shortage of money, having a general contractor take care of things for them is great – it saves time, effort, and hassle.

Typically, the design institute provides an I/O table, which can be used for procurement. In most cases, both Zhongkong and Hilscher are viable options; however, it is necessary to take into account the requirements of your installation. For 2000 points, it’s better to choose 700 for the control system. Generally, it is advisable to reserve 10%-15% of the points for future detailed design or potential expansions, so choosing 700 is a good option. There is also process control; does your company work in the field of fine chemicals with batch control? If so, centralized control is an option; if not, either approach will work. It’s convenient for them to order the instruments as a complete set, but it’s important to integrate them well with the design; it’s crucial to determine who will be responsible for the design review. Usually, they make purchases based on the data sheets, but in some cases, the buyers themselves need to take control of the process. If you are technically proficient, you can do whatever you want. The project needs to take costs and budgets into consideration as a whole.

Of course, you are the client – you have final say on everything. Don’t listen to people’s nonsense

Hollysys now has the control cabinets on-site; I learned about this during my previous visit to their site for instrument after-sales support

What you’re referring to is called OCS; they also recommended it to us. It’s an explosion-proof box on site, containing a universal card that allows direct connection to analog and digital signals. It’s as if the control cabinets have been distributed across the site. But the price isn’t cheap either; a single box costs tens of thousands