Product details

Technical information :

• DSTD 120 Connection Unit for Digital Output Board
  32 channels, max 60 V
  
• Product Net Depth / Length:
• 324 mm
  
• Product Net Height:
• 54 mm
  
• Product Net Width:
• 157.5 mm
  
• Product Net Weight:
• 0.365 kg

A-machine and A-modem are your computer and demodulator, and B-machine and B-modem are dial-up servers at one end of the telecommunications office. After the connection, the computer and the telecommunications office end of the dial-up server to establish a physical connection, on the basis of the physical connection, you can enjoy the Internet service.

Modems used on ordinary telephone lines are called analog modems. A 56K analog modem has a theoretical maximum download rate of 53,333Bps on a regular line, while a maximum upload rate of 33.6KBps.

On a normal phone line, connect with two 56K modems, with a maximum connection rate of 33.6K. This is because the A-modem download is an upload to the B-modem, and the B-modem download is an upload to the A-modem. Limited by a modem upload rate of up to 33.6KBps on a regular line, the maximum connection rate is 33.6K. Most of the 33.6K modems have been discontinued.

On ordinary telephone lines, with 163, 167 and other ISPs that provide 56K access, you can usually achieve a connection speed of about 50K. This is because the Modem at 163, 167 and other offices is a digital Modem, and if it is combined with a suitable Modem, it can reach or exceed the theoretical value on the ordinary line with good quality.

PLC and DCS system in common

①DCS: Distributed control systems (distributedcontrol systems).

PLC: Programmable Logic Controller (PLC). Both have different emphasis and are advanced.

②DCS focuses more on the process control field (such as chemical, smelting, pharmaceutical, etc.) is mainly the monitoring and adjustment control of some field parameters, while PLC focuses on logic control (machining class). Of course, the current PLC can also deal with process control problems well, but there is no DCS professional.

(3) If the simulation quantity is greater than 100 points, DCS is generally used; If the analog quantity is within 100 points, PLC is generally used.

DCS is a "distributed control system", and PLC is just a control "device", the two are the difference between "system" and "device". The system can realize the functions and coordination of any device, and the PLC device only realizes the functions of this unit.

The DCS network is the central nervous system of the whole system, DCS system usually uses the international standard protocol TCP/IP. It is a safe and reliable double redundancy high-speed communication network, the system is more extensible and open. Because the PLC basically works for a single small system, when communicating with other PLC or host computer, the network form used is basically a single network structure, and the network protocol is often inconsistent with international standards.

All I/O modules of DCS system are equipped with CPU, which can realize the acquisition and output signal quality judgment and scalar transformation, fault charging, random replacement. The PLC module is just a simple electrical converter, there is no intelligent chip, and the corresponding unit is all paralyzed after the failure.

ABB series of products