ENGI-7680 Laboratory Experiments

Transcription

1 ENGI-7680 Laboratory Experiments Dr. Vlastimil Masek March 22, Experiment 1.1 Exercise - HMI with Voice Output Use a C library for text-to-speech conversion Flite which is documented at Modify the code to use a function {ite_text_to_speech(const char *text, cst_voice *voice, const char *outtype);} which will generate a voice output of: 1. the current time upon pressing T on the keyboard, 2. the group student names upon pressing N, 3. or exit the program when Q is pressed. Demonstrate your system and include a block diagram with your code. List only the important (modied) parts of your program. 1.2 Exercise - Serial Port Setting Using cutecom or minicom terminal program, check your USB serial adapter using the loopback test. After plugging in the USB to RS232 converter, issue command dmesg tail to see where your converter is mapped. Then write this name, i.e. /dev/ttyusb0, into the CUTECOM device window as it may not be included in the drop down menu by default. 1. Set the device to ttys0 or ttyusb0 2. Set comm parameters to 9600/8-N-1 3. Set the receive-window dispay to hexadecimal mode 4. Send a single ascii character A and record the received code. 1

2 5. Repeat the previous operation while you record the loopback signal on your scope screen in single shot mode. 6. Change the comm parameters setting to 19200/8-E-1 and record the waveform on your scope for ascii character A again. 7. Explain your ndings. 1.3 Exercise - Text-to-Speech 'Skype' Develop a program that will use a serial port for passing a typed message to another party over USB serial link and convert any received message to a voice output. Each message shall also include a time stamp. Demonstrate your system and include a block diagram with your code. List only the important (modied) parts of your program. The code provided was derived from the section on Canonical Input Processing listed in the following document: ˆ Serial Programming HOWTO: #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <termios.h> #include <stdio.h> /* baudrate settings are defined in <asm/termbits.h>, which is included by <termios.h> #define BAUDRATE B9600 /* change this definition for the correct port */ #define MODEMDEVICE "/dev/ttyusb0" #define _POSIX_SOURCE 1 /* POSIX compliant source */ 1. Other references: ˆ Serial Programming Guide for POSIX Operating Systems ˆ usb_serial_port.c - JanAxelson 2

3 2 Experiment - ClassicLadder PLC and Modbus ˆ Objective Building on the knowledge learned in the class, Lab 2 uses the MOD- BUS communication protocol to communicate between a MASTER PLC and multiple SLAVE devices. The rst exercise leads to analysing a serial communication with MOD- BUS. In the second exercise, multiple PLC's will be inter?connected over TCP/IP based Modbus+ protocol. The Modbus+ protocol designates one machine as a master unit and the other linked machines as slave units. The master can read and write variables in all slave units. 2.1 Preparation ˆ Running live GNU/Linux OS, download 'classicladder-xxx.tar.gz' here: ˆ Unpack the le % tar xvzf classicladder-xxx.tar.gz ˆ Change directory to classicladder-xxx % cd classicladder-xxx ˆ Install GTK library (skip this step and come back if needed) % sudo apt-get install libgtk2.0 ˆ Compile sources: % cd src % make clean % make % cd.. ˆ Run classicladder:./classicladder 3

4 2.2 Exercise: MODBUS over serial link ˆ plug two USB serial adapters in your PC ˆ open ClassicLadder PLC (MASTER, ttyusb0) ˆ open CuteCom Serial Terminal (SLAVE, ttyusb1) 1. Congure MASTER (ClassicLadder): ˆ Open Cong window and select Modbus communication tab: Modbus master serial port /dev/ttyusb0 serial baud rate 9600 serial nbr data bits 8 serial parity none serial nbr stops bits 1 after transmit pause-milliseconds 0 after receive pause-milliseconds 100 request timeout length-milliseconds 500 use RTS signal to send no modbus element oset 1 debug level verbose read inputs map to %I read coils map to %Q write coils map from %Q read input registers map to %IW read hold registers map to %QW write hold registers map from %QW ˆ Select the Modbus slaves tab and set the slave No 0 addr to 12. ˆ Create a simple ladder logic on the master having input %I0 mapped directly to %Q [%I0] (%Q0) Write coils Cong: Slave No 0:SerialAddr12 Request Type WriteCoils(from %Q) 1st Modbus Ele 1 4

5 Nbr of Ele 1 Logic 1stI/Q/ 0 3. Write Coils to Slave: ˆ First we use the write coils function to SLAVE No 0 (address 12) While setting coil Q0 on master to 0, then 1, and then to 0 by means of the %I0 variable, monitor the trac in CuteCom terminal using Hexadecimal display. ˆ Record the packets used for setting and resetting the coil and provide an explanation referring to MODBUS tables. 4. Read coils Cong Slave No 0:SerialAddr12 Request Type ReadInputs(to %I) 1st Modbus Ele 1 Nbr of Ele 1 Logic 1stI/Q/ 0 5. Run the simulation and monitor the trac in CuteCom terminal using Hexadecimal display. Record the packet and provide an explanation referring to MODBUS tables. 2.3 Exercise - PLC comm over TCP/IP and MODBUS+ 1. Run classicladder from a terminal window and open a new program. NOTE: Keep the terminal window open as the received and sent Modbus messages will be displayed in this window which can be useful for debugging. These same steps must be done on both machines (master and slave). 2. Cong the comm parameters On the machine that you wish to designate as slave, execute the following command in the terminal window to nd the IP address of that machine: 5

6 % sudo ifcong Copy down the IP that is shown after 'inet address'. Next, on the master, open the cong window in ClassicLadder and navigate to the Modbus I/O Setup and input the IP address followed by :9502 for port 9502 in the slave address column. 3. Test the communication Set %B1 as a coil on your slave machine and whenever that coil goes high, so will %I0 on the master machine. The %B(n+1) slave variables will set the %I(n) inputs on the master. 4. Develop a control algorithm which will demonstrate an equipment start-stop control using a latching relay. This is executed on slave PLC. However the master PLC will display the status of the equipment and if needed, can stop the equipment remotely. 6

7 3 MODBUS programming ˆ Objective In this lab, you will use a Modbus library implemented in C language. Modbus is a serial communication protocol used for transmitting information over serial lines between electronic devices. The device requesting the information is called the Modbus Master and the devices supplying information are Modbus Slaves. In a standard Modbus network, there is one Master and up to 247 Slaves, each with a unique Slave Address from 1 to 247. Versions of the Modbus protocol exist for serial lines (RTU and ASCII) and for Ethernet (Modbus TCP). Some functions are explained in detail below, for more information refer to { MODBUS APPLICATION PROTOCOL SPECIFICATION V1.1b} Coil Numbers Data Addresses Type Table Name to 270E Read-Write Discrete Output Coils to 270E Read-Only Discrete Input Contacts to 270E Read-Only Analog Input Registers to 270E Read-Write Analog Output Holding Registers Function Code Action Table Name 01 (01 hex) Read Discrete Output Coils 05 (05 hex) Write single Discrete Output Coil 15 (0F hex) Write multiple Discrete Output Coils 02 (02 hex) Read Discrete Input Contacts 04 (04 hex) Read Analog Input Registers 03 (03 hex) Read Analog Output Holding Registers 06 (06 hex) Write single Analog Output Holding Register 16 (10 hex) Write multiple Analog Output Holding Registers 3.1 Exercise - install the library 1. Download libmodbus tar.gz (156.8 KB) from sourceforge.net/projects/libmodbus. 2. Untar the le and read the README.txt le. Libmodbus is a dynamic library to use Modbus dialog protocol with GNU/Linux. LibModbus include master, slave and also serial port conguration functions. The library is working only in RTU mode, so you must to congure every time 8 data bits. 7

8 03 (0x03) read n bytes 04 (0x04) read n bytes 06 (0x06) write 1 byte 07 (0x07) read software status 08 (0x08) line test 16 (0x10) write n bytes 3.2 Exercise - program application 1. Develop software that responds to Master's queries using the Libmodbus library with these parameters: 9600 baud, 8 bit data, 1 stop bit, NO parity. Only the following two functions will be tested: 0x03 0x10 read holding registers write holding registers From each register, only the lower byte will be examined, i.e. the higher byte will be discarded upon reading. The slave database (memory map) will contain the following information: A text message in ASCII that contains the full name and the student number, padded with zeros at the high end. This message will be located at even address registers starting at the oset 0xA0 as shown below for John XXX:. 0xA8 0xA6 0xA4 0xA2 0xA0. n h o J Real-time updated local time/date message in ASCII text format of HH:MM:SS YYYY/MM/DD will be also located at even address registers starting at the oset 0x40 as shown below for 12:31: /02/27: 8

9 . 0x48 0x46 0x44 0x42 0x : 2 1 9

10 4 H/W & MODBUS programming ˆ Objective In this lab, you will program a USB DAQ hardware to interface electrical signals (inputs/outputs) and relay this information over the MOD- BUS which was practiced in the last laboratory experiment. 4.1 Exercise - install the driver This operation is not required when using the lab computers however the steps are listed below in case you wish to conduct some experiments on your own personal computer. The steps below are a short excerpt from a longer description by wjasper@tx.ncsu.edu. sudo apt-get update git clone git://github.com/signal11/hidapi.git sudo apt-get install libudev-dev libusb dev libfox-1.6-dev cd hidapi./bootstrap./configure make sudo make install cd.. git clone git://github.com/wjasper/linux_drivers cd Linux_Drivers sudo cp 61-mcc.rules /etc/udev/rules.d/ sudo /sbin/udevadm control --reload-rules cd USB/mcc-libusb/ make sudo make install sudo ldconfig "plug in USB-1208LS hardware and run the test below" sudo./test-usb1208ls 4.2 Exercise - study the test code and H/W manual 1. Review the pinouts of USB-1208LS interface on page 9 of mccdaq.com/pdfs/manuals/usb-1208ls.pdf 2. Review the code at Linux_Drivers/USB/mcc-libusb/test-usb1208LS.c in particular the switch case d and t. 10

11 3. Test the digital I/O by running the./test-usb1208ls under d option. 4.3 Exercise - USB-1208LS at MODBUS slave 1. Combine the MODBUS slave code with with the USB-1208LS code and compile. Periodically scan the input on port B and send the data along with your name(s) as was the case in Lab 3. The Master will read 50 characters so make your string t this size. 2. Attach a push button switch from pin 30 to pin 32 with a 10k resistor in series: # o -- o --- R --- # Demonstrate your code that sends the switch status upon master's request. 4.4 Voice output at MODBUS master 1. Combine the MODBUS master code with Flite text-to-speech library (lab 1) and compile. The Master will voice the string received from a slave device. 2. Demonstrate your code. 4.5 Conclude your report! 11