Secondary Developable Serial Device Server

Published Time: 2013-02-11 Author: Shanghai ZLAN Views: 5236

Common serial device server is a transparent data forwarding converter of TCP/IP to serial port. For different applications, different protocols can only be realized through different software of PC (upper computer). In some cases, however, this simple, transparent serial server no longer meets the requirements:
1) Large amount of equipment polling: if a upper computer needs to poll hundreds of lower computer, it will be a long time for polling, which cannot meet the real-time requirement.
2) Local control function: the serial device server directly controls the serial port device, and does not need the upper computer to determine whether to execute the control command.
3) Protocol conversion is required: the upper computer software protocol is not compatible with the lower computer software protocol.

Shanghai ZLAN provides two kinds of serial device server: ZLAN5132EX and zlan5102-M. Here are the following:

ZLAN5132EX is one of the first developed serial device server of ZLAN. Its main application is the automatic polling of slave RS485 device. This can reduce the workload of the upper computer polling. For example, there are thousands of serial device servers on the network that need to upload data from the slave RS485 device to the upper computer, and each serial device server have 32 slaves. If you ask the upper machine to poll one by one, it's obviously too slow. Using ZLAN5132EX, you can automatically send the polling instructions, and the polling instructions and polling time can be set. Another addition function of ZLAN5132EX is to support the download of custom web pages.

ZLAN5132EX design polling instruction uses the ZLFsCreate tool of ZLAN, which can input the hexadecimal code of each instruction and the polling interval. When the design is finished, download the design files to ZLAN5132EX for internal execution. Another important characteristic is that ZLAN5132EX support polling pause function when slave device gives response, namely when the slave device gives response, the serial device server does not continue to poll for the next slave device, but wait for finishing uploading the data of slave device then polling. The data uploaded from slave device will be directly forwarded to the Ethernet port and uploaded to the upper computer.

ZLAN5102-M is a secondary development serial device server with more powerful functions. It not only supports the polling of instructions, but also performs corresponding actions based on the response data from the slave devices. That is, local control and protocol conversion can be achieved.

ZLAN5102-M is embedded a secondary development MCU inside, the MCU has two serial ports, one of the serial port connect with ZLAN ZLSN2002 core module of serial to Ethernet, the other serial port connect with ZLAN5102-M external serial port. The MCU can actually realize the data transformation between serial port 1 and serial port 2. ZLAN provides a suite of secondary development of the MCU, the development CD-ROM contains all kinds of protocol conversion example code, can be convenient for the user to develop needed function of local control, protocol conversion under this basis.