This article introduces the application of ZLAN Serial Device Server in substation to realize the network monitoring and remote monitoring of substation control devices.
LAN transformer substation monitor as shown in figure 3-1, connect the serial port of multiple transformer control devices with our ZLAN5400, then ZLAN5400 establishes network connections with the monitoring host in the local area network (LAN), the serial data will be transferred to network data and sent to the monitoring host. On the monitoring host, we installed our ZLVircom software, create virtual COM port to bind our device, and convert the network data into serial data. The upper computer software communicates directly with the virtual serial port.
The remote control of the substation is shown in figure 2. After connecting the serial port device to ZLAN5400, the serial port data is converted into the data on the network. ZLAN5400 access to network and connect to a remote monitoring host via a public network. Then, create virtual serial port through ZLVircom and do communication through serial port.
The advantages of using ZLAN serial device server to do serial port communication compared with direct communication between serial port and serial port are:
For remote monitoring of PLC by using the Siemens integrated development environment Micro-win STEP7, please select the virtual serial number of the monitored PLC in PC/PPI configuration. Note: if you are using the Internet for monitoring, please consult ZLAN engineer for details of 《Method of improve the waiting time for querying PPI protocol of Micro_WIN》 if you configure STEP7.
1、The communication distance of the serial port is short, and the RS232 serial communication is more than ten meters, and the RS485 is more than 1200 meters. After joining ZLAN serial device server, the serial port data is sent to the network, so that the communication distance is not restricted.
2、There is only one or two serial ports on the monitoring host. If need monitoring multiple substation control devices, the number of serial ports on the monitoring host is not enough. But after joining ZLAN serial device server, multiple substation control devices can be connected to one or more serial device server, by network cascade, implementing a monitoring host monitoring many sets of transformer control devices.
3、It can be controlled and debugged remotely, and can be remotely adjusted to avoid the waste of time when the transformer control device is in trouble. Save time and cost.
Remote control features of ZLAN serial device server:
1、Support the internet-based monitoring, the ZLAN serial device server supports the domain name, and combined with the dynamic domain name system provided, can realize cross-internet monitoring.
2、Support remote configuration parameters, and even in the cross-Internet mode, you can remotely modify the device name, device IP, serial port parameters, etc.
3、On-the-fly technology: ZLVircom supports the on-the-fly technology, so that user don't need to know the port number of serial ports, check bits and other parameter series, and the serial device server can be identified automatically.
4、Network recovery mechanism: under the Internet-based scheme, the network recovery mechanism must be supported, using the Realcom protocol of ZLAN can solve this problem.
5、Full duplex, zero packet loss technology: ZLAN serial device server is full duplex, can send 1G data continuously without losing a byte at the work circumstances of highest baud rate, full duplex and uninterrupted.