This example is based on the hardware S7 bus analysis function of BCNet-S7200-S or BCNet-S7300-S to realize the detection of touch screen data points and analyze the important point table information of current PLC in combination with the panel information of touch screen.
BCNet-S7300-S is used for Siemens S7-200, SMART S7-200, S7-300, S7-400 series PLC Ethernet data acquisition, which is very convenient to build a production management system. The module integrates WiFi function and supports AP mode, STA mode and AP+STA mode, which is very convenient for building WiFi network and PLC programming and data acquisition directly through WiFi.
BCNet-S7-300-S adopts industrial grade design, rail mount with communication cable. BCNet-S7-300-S supports most SCADA software in industrial control field and supports Siemens S7 Ethernet protocol, ModbusTCP master-slave and BCNetS7 Ethernet communication mode.
Hardware connection
1,As shown in the figure, the original system is a touch screen connected to the PPI interface of S7-200. Now, without changing the original system, the BCNet-S7200-S module is added to realize Ethernet data acquisition, PLC programming and data exchange functions between different PLCs.
For the S7-200 touch screen, BCNet is divided into two types of bridged and straight through, and can be bridged and straight through selected by the “bridge/thru dip switch”, in general, the domestic touch screen selects the bridged type, and Siemens and other multi-master protocol touch screen selects the straight through type.
2,As shown in the figure the original system is S7-300 MPI multi-master system, without changing the original system, BCNet-S7300-S module is added to realize Ethernet data acquisition, PLC programming and data exchange functions between different PLCs.
Detection of non-Siemens touch screen (such as MCGS touch screen) connected to S7-200 point table
1, the current touch screen screen there are two variables, “current temperature” and “warning temperature”, both single-precision floating-point data, connected devices for S7-200 (CPU224XPCN).
2,run “BCDeviceV1031.exe”, search for the BCNet-S7200-S module, and click “Device Operation Diagnosis”.
3, in the device operation diagnosis, you can see that there are two devices in the S7 bus, device 0 is the master, i.e. BCNet-S7200-S module, device 2 is the slave, i.e. S7200-CPU224, click the “Point Table Detection” button.
4,Enter “BCNet888” in the pop-up authority authentication window to enter the S7 bus analysis interface, as shown below.
①Floating-point data is selected from the touch panel, and two types of resolution are provided, namely “floating-point 32-bit” and “floating-point 64-bit”, i.e., single-precision and double-precision floating-point, and “floating-point 32-bit” is selected here. “.
② site information prompt for “bridge HMI read PLC”, indicating that the current touch screen is through the bridge mode of communication, that is, through the BCNet-S7200-S transit mode of communication.
③ can see the current data stream “30.3” and “38.9” corresponding to “VD200” and “VD102 “, through the touch panel information, we can know that “VD200” corresponds to “current temperature” and “VD102” corresponds to “warning temperature”. “warning temperature”.
④ The current list can be exported to an Excel file for further editing and processing.
5, the “warning temperature” of the touch screen is set to “39.5”, through the BCDevice tool can detect the current HMI to the PLC “VD102” The behavior of writing “39.5” to the PLC through the BCDevice tool.
Detection of Siemens touch screen with S7-300 point table
1, sample configuration Siemens KTP1000BasicDP touch screen as follows, the connected PLC for the CPU315-2DP, in order to demonstrate the detection function of this module, so the configuration screen read DB1.DBW0 ~ DB1.DBW18 integer variables, MW0 ~ MW2 integer variables and Q0.0 ~ Q0.1 Boolean variables.
2,run “BCDeviceV1031.exe”, search for the BCNet-S7300-S module, and click “Device Operation Diagnosis”.
3, in the device operation diagnosis, you can see that there are three devices in the S7 bus, device 0 is the master that is BCNet-S7300-S module, device 2 is the slave that is S7300-CPU315-2DP, device 1 is KPT1000 touch screen; click the “point table detection” button.
4,Enter “BCNet888” in the pop-up authority authentication window to enter the S7 bus analysis interface, as shown below.
①The site information prompt is “Master 1 reads Master 2”, indicating that the current touch screen is a multi-master communication, from the “equipment operation diagnosis” page can be seen that Master 1 is KPT1000 touch screen, Master 2 is S7300 PLC.
② from the touch screen panel can be seen to select signed integer data, providing “signed 16-bit” and “signed 32-bit” and other types of integer resolution, here select “signed 16-bit “.
(③) The current data stream can be compared with the touch screen panel information, which can be visually derived from the current screen of the touch screen to read the S7300 corresponding point list information.
④ the current list can be exported as an Excel file for further editing and processing.
5,The Q0.0 of the touch screen is set to operate, through the BCDevice tool can detect the behavior of the current HMI to PLC “Q0.0” set.
Through the hardware S7 bus analysis function of BCNet-S7200-S or BCNet-S7300-S, the current data flow of S7 bus (PPI, MPI and DP bus) can be analyzed to detect the current reading and writing behaviors of the touch screen, and the important point table information of PLC can be derived by combining with the panel information of the touch screen; through this method, the point table information of multiple PLC sites can be read by the touch screen and the information of data exchange between multiple PLCs can also be detected.