C002292.01 9100131600 VB-430 six sets of low-voltage electric control cabinets placed in situ, used to complete their respective fan subsystems, such as start and stop functions; PLC remote self-control cabinets a set of the choice of Siemens S7-300 series, the collection of the entire fan system of temperature, flow, oil pressure, and other analogue quantities through the upper computer output display, alarm.

C002292.01 9100131600 VB-430 There are many temperature collection points in the fan system. In this project, each set of fan has 3 motor stator temperatures, 2 motor support bearing temperatures, 2 fan support bearing temperatures and 1 thrust bearing temperature, with a total of 48 temperature points. If the Siemens 8-point analogue input module is selected, a total of 6 pieces are required. (As shown in Figure 1.) Together with the analogue inputs such as shaft vibration degree, oil pipe pressure, outlet air pressure, etc., the number of analogue input modules of PLC to be selected is too many, which is costly and difficult to install.

C002292.01 9100131600 Some of the CPUs of the VB-430 series PLCs are equipped with PROFIBUS DP master/slave interfaces, so we can use the PROFIBUS bus transmission protocol to obtain field temperature signals in bulk.PROFIBUS -DP is used for high-speed data transmission at the field level. The master cyclically reads the inputs from the slaves and cyclically sends the outputs to the slaves. The bus cycle time must be shorter than the master (PLC) programme cycle time. In addition to cyclic user data transfer, PROFIBUS-DP provides the non-cyclic communication required by intelligent devices for configuration, diagnostics and alarm processing. Diagnostics and alarm processing.