The purpose of this project is to design and implementation of a 16-Floor Control System using two DELTA and Siemens PLCs plus two Weinview and Panelmaster HMI devices. This project is an, upgraded version of my previous elevator simulator system, which was published about two years ago: Implementation of an 8 Floor Control System with a PLC. To read more about that project, click HERE.
To view the Micro-controller-based Elevator project in action, click HERE.
The main reason I’ve decided to redo the Elevator Control System is that, in the past, spent a lot of time to build hardware fixture of the project, and it was very costly and time-consuming.
In the hardware structure of the new 16-Floor Control Simulator System, many of the issues in dealing with the hardware of the elevator system have been resolved. In the upgraded version one, I am using a primary DELTA PLC to generate required input/output signals that used to come from the Cabin traveling sensor. Similarly, signals are sent from the DELTA PLC to simulate cabin movement or Cabin’s door.
In short, in this project, I am using a primary DELTA PLC and a VEINVIEW HMI device to simulate all signals coming from the hardware fixture of the elevator. As I mentioned earlier, I am going to use a second SIEMENS S7-300 PLC to execute the main control program to exchange data with the primary PLC, and the main HMI device which also simulates the main elevator keyboard, Auto/Manual hammer switch, Cabin door, Cabin light, emergency limit switches and a two 7-segment display indicator (to show the current floor number). See Figure 1.
Figure 1 displays the wiring schematic of the primary DELTA PLC.
Notice that the input signals that the main PLC used to send to the mechanical elevator fixture, must be sent to input ports of the DELTA PLC (X0 to X7) in this version. As an example, when the elevator Cabin door is Opened, the PLC needs to just activate X1 input. Activating CW and CCW inputs (X2, X3) simulates an elevator Cabin which is traveling either clockwise or counterclockwise. By either turning on the X4 or the X5, the main PLC can control the speed of rotation of the hand indicator; hence we can simulate the speed of Cabin when it is traveling up or downward.
Figure 2: displays how I/O terminals of both PLCs should be connected to get the whole system to function as designed.
Notice that in Figure 3, the four output terminals (Y0, Y1, Y4, and Y5) of DELTA PLC are gated by four NOT gates prior to their connection to the input terminals of the Siemens S7-300 PLC (second PLC). The reason is that output ports of the DELTA PLC are “open collector” outputs, which are the unconnected Collectors of NPN transistors, made available to the external circuitry, that switch to ground when active. Since the inputs of “second PLC” are active “high”, we needed to “NOT” all of those used output signals coming out of DELTA PLC. I used 4× 4n35 ICs to invert all those signals as shown in Figure 3.
The table shown in Figure 5 explains the designations of IN and OUT terminals of the DELTA PLC. It means, if we connect one end of a loose wire to +24 V DC and the other end to any of the designated input terminals, we can see the related action happening on the “primary HMI”. For example, connecting the second end of the wire to X0 or X1 causes the door image on the HMI to be “closed” or “opened” respectively. Connecting the wire to X2 and X4 causes the floor hand indicator to “rotate” clockwise with a “slow” speed. Also when the “cabin” door is completely closed or opened, either Y3 or Y4 will turn on respectively.
Actually, after downloading the “main control PLC” program into the S7-300 PLC user memory, all these related input signals will get generated by the “second” PLC, depending on in what orders they are issued by the “keypad” on the “second HMI”. Input / Output PLC Terminals designation of the DELTA PLC is shown in Figure 5.
Notice that in Figure 3 we are using two limit switches, which are connected to I0.2 and I0.3 which are designated as input terminals of the S7-300 PLC. In the old version of the 8 Floor Elevator Control System project, I was using these two limit switches to alert the operator anytime the elevator “cabin” reaches higher than the 16th or lower than the 1st floor. The cases such as these are considered as ‘Emergency’ status, and in this case, the hardware and any control software of these types of an industrial system must inform the operator when those abnormal events happen.
I have installed two limit switches designated as ‘ER limit switch up’ and ‘ER limit switch down’ that will get activated any time the ‘cabin’ reaches a position (in either Auto or Manual mode) too high or too low.
Four control programs are generated for this project to do the following functions:
(1) 16Floor_HMI.mtp program is to bring out the graphic shown in Figure 1, and is related to the HMI (WEINVIEW model MT6070 IH) device to communicate with DELTA PLC.
(2) 16Floor_PLC.isp program is developed for DELTA PLC (model DVP20SX2) to receive inputs from S7-300 PLC and generate related output signals.
(3) HMI_16FloorElevator.pm2 is prepared for the second HMI (7 inches LCD touch screen PanelMaster model P1070 800×480 pixels) display, which is connected to S7-300 PLC.
(4) 16_floor.s7p program is developed for Siemens SIMATIC S7-300 PLC, which controls the second HMI and communicates with DELTA PLC.
How to set up hardware and download files to PLCs and HMIs?
1-After you have connected the wires to I/O ports of two PLCs as shown in Figure 1, you need to connect your RS485 cable to each HMI device and download the mentioned files to each display device using your PC.
2-Use your second cable (which might be different for each PLC) to download the two PLC control programs.
3-Connect each related HMI device cable to the suitable port of the PLC that the user manual of that particular brand recommends.
4-On the second HMI device put Auto / Manual switch on Manual, and verify whether you are able to open or close the door image or not. If everything goes well, all functions will work properly, and you will enjoy experiencing how well the project is functioning just like an obedient servant! The zipped folder containing these 4 files is named: “16 Floor Project”.
Figure 6 illustrates the designated control program which is developed for each PLC and HMI device in this project.
To download the developed program files for this project, Click HERE