C819 IOx Modbus RTU Client Application Setup Guide

Transcription

1 IoT Cisco C819 IOx Modbus RTU Client Application Setup Guide OVERVIEW Cisco IOx is a framework that supports the capabilities to compute, store, and analyze data from the network edge to the cloud. Businesses can bring their own applications and interfaces to their networks to customize processes and react quickly to changes in conditions, competition, supply chain, or customer preferences. Cisco IOx brings together Cisco IOS, the industry-leading networking operating system, and Linux, the leading open source platform. Cisco IOx offers developers a way to create IoT applications such as data aggregation, control systems, and access control and have them run on edge network devices. The Cisco 819 (C819) Integrated Services Router supports machine-tomachine (M2M) applications that can enable enterprises to use 3G/4G wireless WAN network services to go beyond traditional branch locations. Extend your corporate network to the micro branch for applications like automated teller machines (ATMs), kiosks, digital signage, or remote branches. Modbus is a serial communications protocol originally published by Modicon (now Schneider Electric) in 1979 for use with its programmable logic controllers (PLCs). Simple and robust, it has since become a de facto standard communication protocol, and it is now a commonly available means of connecting industrial electronic devices. This tutorial demonstrates how to run a sample Modbus RTU client application to measure the temperature sensor attached to an external analog IO module through the 12-in-1 serial port on C819. It covers the hardware components and environment setup, configuration, detailed steps, tools, troubleshooting, etc. Related URLs: IoT DevNet Communities: C819 IOx SDK Cook Book: docs/doc Cisco 819 Integrated Services Router: IoT DevNet Contact: For additional help, please contact the IoT DevNet support team at iot-cdn-support@cisco.com Cisco and/or its affiliates. All rights reserved. Page 1 of 21

2 1. PREREQUISITES Hardware components including C819 router, TMP36 temperature sensor, analog I/O module, RS232-to- RS485 converter, DB25-to-DB9 converter, DB9 Male-to-Male crossover adapter (if necessary), Cisco CAB- SS-232FC cable, and DC power supply. C819 is connected to a switch for network access, and is available for console access or SSH access. C819 IOx SDK is installed and functional Developer should be familiar with o How to interact with IOS and IOx feature o How to use the IOx UI Interface o How to develop and test the application of C or Python language in Linux environment 2. SETUP ENVIRONMENT In the hardware environment, it includes the components of C819 router, TMP36 temperature sensor, analog I/O module, RS232-to-RS485 converter, DB25-to-DB9 converter, DB9 Male-to-Male crossover adapter (if necessary), Cisco CAB-SS-232FC cable, and DC power supply. Here is the example for the real setup environment with the example component models. 2.1 PHYSICAL ARCHITECTURE The architecture includes the TMP36 sensor for temperature data gathering, ADAM for IO analog module monitoring and measuring with Modbus, the related converter for physical connection, and C819 IOx for Modbus mastering, data analysis and processing. ADAM is an analog IO module with Modbus support over RS485 interface, and Cisco C819 supports Modbus over RS232 interface. So it needs a RS232-to-RS485 converter to make these two interface connected. Due to the real models of serial interface, it may need the DB9-to-DB25 converter and DB9 Male-to-Male crossover adapter (if DB9 interface of RS233-to-RS485 and DB9-to-DB25 converters are both Female) as well. For the detail information of the related components, please refer to Chapter Cisco and/or its affiliates. All rights reserved. Page 2 of 21

3 Figure 1: Physical Architecture and Connection 3. PROCEDURE In this chapter it will cover the following steps in details: 1) Setup the hardware environment including how to connect the sensor and the analog IO module to C819 2) How to configure serial raw-socket in C819 IOS 3) Write a sample Modbus RTU Client application 4) Create a makefile to compile the application using the tool-chain 5) Upload the application to the IOx device 3.1 CONNECT THE SENSOR TO C819 Make all the related hardware components ready, and follow the Chapter 2 for the hardware environment setup to connect the sensor to C819. Here are the detailed steps. For more details, please refer to Chapter 2 and 4. 1) Connect TMP36 temperature sensor to an analog IO module. We have an Advantech Adam module in our setup. o AS the ADAM is set to the protocol of ADVENTECH by default. Use ADAM Utility to set the protocol to MODBUS in Init, and power on again in Normal for enabling. And make sure the Baud Rate is 9600 bps and the Address is 1. For details, please refer to Chapter 5.1 ADAM Utility Tool. o Connect Vin0+ and Vin0- to the TMP36 sensor with pin2 (Analog Voltage Output) and pin3 (GND). Here the first channel is used as the analog input for example. Figure 2: ADAM connects to TMP36 2) Connect the analog IO module to C819 faceplate serial port. o Since RS485 is not supported by the C819 serial interface, we use a RS232-to-RS485 converter between the ADAM IO module and C819 serial port. Connect Data+ and Data- to RS485-to-RS232 Converter with the respective pins of Data+(T/R+) and Data-(T/R-). o C819 comes with the cable of CAB-SS-232FC with female connector. It has 26-pin on Cisco end, and a standard DB-25 connector on the other end. So it needs a DB9-to-DB25 converter to connect DB9 of 2015 Cisco and/or its affiliates. All rights reserved. Page 3 of 21

4 RS485-to-RS232 Converter. And it may need a DB9 Male-to-Male crossover adapter for the connection of RS232-to-RS485 converter and DB9-to-DB25 converter in case of both DB9 ports are Female. Figure 3: ADAM connects to RS485-to-RS232 Converter 3) Connect to the power supply and power on for TMP36 senor, ADAM 4017+, converter (if necessary), C819, etc. o If there is no standard DC Power Supply available, you may simple use a DC12V power adapter for ADAM Check the negative/positive information in the guide of the power adapter. Usually the inside polarity of the power jack is positive voltage (+), and outside is negative voltage (-). Figure 4: AC/DC 12V Power Adapter and Polarity (as an example) 3.2 CONFIGURE SERIAL RAW-SOCKET TRANSPORT IN IOS Make sure IOx is installed in C819. You may check it with the command of show version to get the running version. The IOx version should be like System image file is flash:c800-universalk9_iox-mz.spa t1.bin. Remote access by SSH or console access to C819, and configure raw-socket TCP under serial interface and the corresponding async line. The sample configuration below shows how to connect serial port s0 on C819 to guest: 2015 Cisco and/or its affiliates. All rights reserved. Page 4 of 21

5 interface Serial0 physical-layer async no ip address encapsulation raw-tcp! line 7 raw-socket tcp client where: " " is the host IP address configured in "host ip address" command under IOx submode after you run show running-config. "32000" is the serial TCP port described in the VM description file (xml from OVA) Host IP address information after running show running-config : iox host ip address host ip default-gateway Serial information in test.xml of the ova application: <serial type='tcp'> <source mode='bind' host='' service='4444'/> <target port='32000'/> <protocol type='telnet'/> <alias name='serial0'/> </serial> The below diagram shows the data flow between the sensor and the guest application. Figure 5: The Data Flow Between the Sensor and the C819 Guest Application 3.3 A SAMPLE MODBUS RTU CLIENT APPLICATION libmodbus library (version 3.0.6) is already included in guest rootfs image (You can download the source and include files from: and it will be installed to /usr/lib of the Guest OS Cisco and/or its affiliates. All rights reserved. Page 5 of 21

6 Here is sample Modbus RTU client application (modbusrtuclient.c) to read the sensor data periodically and displays the temperature value on guest console. /* * Sample modbus RTU cient program to demonstrate * how to access the external serial device from guest * how to read sensor data using modbus RTU protocol * * A TMP36 temperature sensor is connected to channel 0 of an 8-channel analog I/O module. * * Copyright (c) 2014 by Cisco Systems, Inc. All rights reserved. * */ #include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <time.h> #include <unistd.h> #include modbus.h #define MODBUS_SERVER_ID 0x01 #define MAX_NUM_SENSORS 8 #define NUM_SENSORS_INUSE 1 #define TEMP_SENSOR_CH 0 /* * Get the sensor voltage reading using MODBUS RTU */ int read_sensor_data (modbus_t *ctx, double *sensor_val) { int ret; unsigned short tab_reg[64]; uint ch; } ret = modbus_read_registers(ctx, 0, NUM_SENSORS_INUSE, tab_reg); if (ret < 0) { printf("failed to read registers ret %d\n", ret); return -1; } for (ch= 0; ch < NUM_SENSORS_INUSE; ch++) { sensor_val[ch] = (double)tab_reg[ch]; } return (ret); int main(int argc, char *argv[]) { modbus_t *ctx = NULL; double sensor_val[max_num_sensors]; double tempval; 2015 Cisco and/or its affiliates. All rights reserved. Page 6 of 21

7 if (argc < 2) { printf("usage: %s device_node\n", argv[0]); exit(-1); } /* creat context for libmodbus */ ctx = modbus_new_rtu(argv[1], 9600, 'N', 8, 1); if (ctx == NULL) { printf("unable to allocate libmodbus context\n"); exit(-1); } modbus_set_debug(ctx, FALSE); /* connect to modbus master */ if (modbus_connect(ctx) == -1) { printf("connection failed: \n"); modbus_free(ctx); exit(-1); } modbus_set_slave(ctx, MODBUS_SERVER_ID); printf("connection to Modbus server successful\n"); } while(true) { if (read_sensor_data(ctx, sensor_val) < 0) { sleep(1); continue; } tempval = sensor_val[temp_sensor_ch]; /* convert the reading to millivolts */ tempval = (tempval ) / * 1000; /* convert from millivolts to centigrade */ tempval = (tempval - 500) /10; printf("\n\ttemperature %.2fC %.2fF", tempval, (tempval * 9 /5 + 32)); sleep(1); } If you are using Python instead of C, you need to install the latest version of C819 IOx SDK of iox_sdk_installerx86_64-v bin. In the SDK, app-03 provides you with the make file to build the Python2.7 interpreter and a set of default modules. Download pyserial (version 2.7) and minimalmodbus (version 0.6) packages from and Copy the compressed tar balls to app-03/gpl/python-modules, and add the module name to MODULES_LIST in Makefile as follows before you build the OVA. MODULES_LIST=CherryPy six psutil pyserial-2.7 MinimalModbus-0.6 \ Go to the app-03 directory (/opt/ciscoiox/cisco_iox_sdk-x86_64-v0.1/examples/apps/app-03/), and run the make command, and it will build the application OVA including python 2.7. For others, refer to the C819 cook book in detail Cisco and/or its affiliates. All rights reserved. Page 7 of 21

8 Here is the sample code in Python. Put it to your C819 guest OS for further running. You may skip the next section in case of Python. import time import minimalmodbus import serial instrument = minimalmodbus.instrument('/dev/vport0p2', 1) instrument.serial.baudrate = 9600 instrument.serial.timeout = 1.0 for count in range(10): tempval = instrument.read_register(0, 0) tempval = (tempval-32770)/ *1000 tempval = (tempval-500)/10.0 print "\ttemperature %.2fC %.2fF\n" % (tempval, tempval*9/5.0+32) time.sleep(1) 3.4 COMPILE AND UPLOAD THE APPLICATION TO C819 Cross-compile using the toolchain in SDK, then upload the binary to C819. Please refer to the cook book at for details. As the file of modbus.h is used in the source code of modbusrtuclient.c, you need to un-package the libmodbus source code of libmodbus tar.gz, get the files of modbus.h, modbus-version.h, modbus-tcp.h, and modbus-rtu.h, and put them into the same folder of source code for further compiling. It also needs the shared objects of libmodbus.so to compile. It is located in /opt/ciscoiox/cisco_iox_sdk-x86_64- v0.1/tools/toolchain/powerpc-linux-gnu/powerpc-linux-gnu/libc/lib/libmodbus.so. If it is not there, copy it manually from rootfs.ext /usr/lib/libmodbus.so into the same folder of source code with renaming to libmodbus.so as well. (Please note the rootfs.ext.xxxxx folder will be created in 4.7 Repackage the prebuilt rootfs with new created application in cook book.) root@ubuntu:/home/ubuntu/iox_c/modbus-src# ls -al rootfs.ext /usr/lib/libmodbus* lrwxrwxrwx 1 root root 18 Apr 24 10:12 rootfs.ext /usr/lib/libmodbus.so -> libmodbus.so.5.0.5* lrwxrwxrwx 1 root root 18 Apr 24 10:12 rootfs.ext /usr/lib/libmodbus.so.5 -> libmodbus.so.5.0.5* -rwxr-xr-x 1 root root Apr 24 10:12 rootfs.ext /usr/lib/libmodbus.so.5.0.5* Here is the file list with the source file, include file, Makefile, and shared objects file. root@ubuntu:/home/ubuntu/iox_c/modbus-src4# ls -al total 104 drwxr-xr-x 3 root root 4096 Apr 24 10:47./ drwxrwxr-x 9 ubuntu ubuntu 4096 Apr 24 10:45../ -rwxr-xr-x 1 root root 767 Apr 24 10:08 imgb_cb_script.sh* -rwxr-xr-x 1 root root Apr 24 10:46 libmodbus.so* -rw-r--r-- 1 root root 1139 Apr 24 10:47 Makefile -rw-r--r-- 1 root root 7866 Apr 24 10:08 modbus.h -rw-r--r-- 1 root root 2560 Apr 24 10:08 modbusrtuclient.c -rw-r--r-- 1 root root 1434 Apr 24 10:08 modbus-rtu.h 2015 Cisco and/or its affiliates. All rights reserved. Page 8 of 21

9 -rw-r--r-- 1 root root 1825 Apr 24 10:08 modbus-tcp.h -rw-r--r-- 1 root root 2031 Apr 24 10:08 modbus-version.h drwxr-xr-x 17 root root 4096 Apr 24 10:12 rootfs.ext / For the Makefile, here is the example. ###### Toolchain Environment Setup ####################### # define where the toolchain is located, it is relative to IOX_SDK_HOME which # is set by the IOx SDK environment setup script which should have been sourced IOX_SDK_HOME = /opt/ciscoiox/cisco_iox_sdk-x86_64-v0.1 TOOLCHAIN_DIR = $(IOX_SDK_HOME)/tools/toolchain/powerpc-linux-gnu # define compilation flag specific to the CPU for the c800 series PLATFORM_CPU_FLAGS = -te500v2 # where the C compiler is at (gcc) CC = $(TOOLCHAIN_DIR)/bin/powerpc-linux-gnu-gcc # typical compilation flags CFLAGS = -Wall -Wshadow -O2 $(PLATFORM_CPU_FLAGS) # define flags for the linker that specifies where the libraries are LDFLAGS = $(PLATFORM_CPU_FLAGS) \ -L$(TOOLCHAIN_DIR)/powerpc-linux-gnu/libc/lib \ -L$(TOOLCHAIN_DIR)/powerpc-linux-gnu/lib/gcc/powerpc-linux-gnu/4.5.1/ SOURCE := $(wildcard *.c) OBJS := $(patsubst %.c,%.o,$(source)) compile: modbusrtuclient.bin modbusrtuclient.bin:$(objs) echo $(OBJS) $(CC) $(LDFLAGS) -lmodbus -o "$(@)" $(^) Compiling $<... $(CC) -c $(CFLAGS) $< -o $*.o.phony: clean clean: rm *.bin *.o -rf 3.5 RUN THE APPLICATION Once you created the new ova with Modbus RTU client application, deploy it on C819 and start it in C819 Local App Manager, access the console of the C819 guess, simple run /usr/bin/modbusrtuclient.bin /dev/vport0p2, and you will see temperature readings on guest console: 2015 Cisco and/or its affiliates. All rights reserved. Page 9 of 21

10 bin]# /usr/bin/modbusrtuclient.bin /dev/vport0p2 connection to Modbus server successful temperature 21.19C 70.15F temperature 22.26C 72.07F temperature 23.76C 74.76F In case of Python, go to the folder where you put the python code, and run python modbusrtuclient.py. Here the device name and related parameters are hardcoded. Please modify the sample code if necessary. bin]# python modbusrtuclient.py temperature 21.19C 70.15F temperature 22.26C 72.07F temperature 23.76C 74.76F 4. HARDWARE COMPONENTS AND CONNECTIONS 4.1 C819 ROUTER (C819HG-4G): It needs a C819 router with IOx installed. IOX is supported to install in C819 with 4G LTE SKUs. For how to install and run IOx on C819, and IOx SDK for C819, please refer to the cook book at C819 supports RS232, and comes with a cable of CAB-SS-232FC (Male DB-60 to Female DB-25, mode - DCE). 4.2 TMP36 TEMPERATURE SENSOR: The TMP36 is low voltage, precision centigrade temperature sensors. It provides a voltage output that is linearly proportional to the Celsius (centigrade) temperature. You may get a TMP36 temperature sensor from Use two batteries in serial for power supple (pin1 and pin3), and connect the voltage output (pin2 and pin3) to ADAM Figure 6: TMP36 temperature sensor 2015 Cisco and/or its affiliates. All rights reserved. Page 10 of 21

11 4.3 ADAM ANALOG I/O MODULE: The ADAM is a 16-bit, 8-channel analog input module that provides programmable input ranges on all channels. These modules are an extremely cost-effective solution for industrial measurement and monitoring applications VDC optical isolation between the analog input and the modules protects the modules and peripherals from damages caused by high input voltages. You may get an ADAM Analog IO Module with Modbus from B749-A395F aspx. Here the first channel is used as the analog input for example. Connect Vin0+ and Vin0- to the TMP36 sensor with pin2(analog Voltage Output) and pin3(gnd). See the left figure of Figure 4. ADAM supports Modbus with RS485 output. Connect Data+ and Data- to RS485-to-RS232 Converter with the respective pins of Data+(T/R+) and Data-(T/R-). See the right figure of Figure 4. Figure 7: ADAM connects to TMP36 and RS485-to-RS232 Converter Make sure Modbus protocol is set before you use it as Analog IO Module in this environment. You need to use ADAM Utility to set ADAM for with Modbus protocol and related. For details, please refer to the chapter of Tools (ADAM Utility). 4.4 RS232-TO-RS485 CONVERTER: You may use any standard RS232-to-RS485 Converter. Here we use ADAM 4520 as an example which needs an additional power supply. You may get it from /mod_8dcee4b7-fbde-4c5d-9752-ed2f2fbd00bf.aspx Cisco and/or its affiliates. All rights reserved. Page 11 of 21

12 Figure 8: ADAM 4520 and one other RS232-to-RS485 Converter You may also use RS232 to RS485 Communication Data Converter Adapter with a Terminal Board (without additional power supply) from Make sure to connect the respective pinouts with the output of Data+ and Data- from ADAM Usually the Data+ (or T/R+ ) of the converter connects Data+ of ADAM 4017+, and the Data- (or T/R- ) of the converter connects Data- of ADAM The output is a DB9 RS232 interface which will connect to DB9-to-DB25 Converter (it may need a DB9 Male-to-Male crossover adapter if necessary). Figure 9: ADAM 4520 Pinouts Connection 4.5 DB25-TO-DB9 CONVERTER AND DB9 MALE-TO-MALE CROSSOVER ADAPTER: As the RS232-to-RS485 converter is DB9 and Cisco cable CAB-SS-232FC is DB25 (Female), it needs a DB25-to- DB9 converter. The converter could be any standard DB25-to-DB9 converter. Please make sure the interfaces should match both interfaces of RS232-to-RS485 converter (DB9 Female) and CAB-SS-232FC cable (DB25 Female). You may get one converter from Adapter/dp/B00066HOWK. In this case, the DB9 of the DB25-to-DB9 converter is Female, and its DB25 is Male. Figure 10: DB25-to-DB9 Converter Theoretically speaking, if both ports are DTE (Male) or both DCE (Female), you need an adapter to connect them directly together. This adapter features Male DB9's on both sides, so it will convert a Female (with holes) DCE Serial port to a Male (with pins) DTE Serial Port. If both devices are DB9 female you will need a crossover cable/adapter Cisco and/or its affiliates. All rights reserved. Page 12 of 21

13 So it needs a DB9 Male-to-Male adapter (crossover) to make both DB9 Female of RS232-to-RS485 converter and DB25-to-DB9 converter connected in this case. (Please note, if the one DB9 is Female, and the other DB9 is Male, then no need for the adapter.) Based on the pinouts definition of DB9 Female and Male, the DB9 Male-to-Male adapter must be crossover, not straight through. You may get one from Modem-Adapter/dp/B006WAA55M/ref=sr_1_6?s=electronics&ie=UTF8&qid= &sr= CISCO CAB-SS-232FC CABLE Figure 11: DB9 Male-to-Male Crossover Adapter C819 supports RS232, and it comes together with a cable of CAB-SS-232FC (Male DB-60 to Female DB-25, mode - DCE). Figure 12: Cisco Cable CAB-SS-232FC 5. SOFTWARE TOOLS ADAM Utility is a tool to configure ADAM 4000 and 5000 serials from Adventech. You may download installation binary from Modbus Poll and Slave are very popular simulators for test and debug. You may download them from the below site: The tools of Modbus Poll and Slave are only for troubleshooting of Modbus protocol. You do not need to use it if everything is working well. Here we just list the key guide for these software tools. For more details, please refer to their official manual or guide Cisco and/or its affiliates. All rights reserved. Page 13 of 21

14 5.1 ADAM UTILITY ADAM Utility is a tool to configure ADAM The ADAM must be configured to MODBUS protocol before we use it in this application setup. 1) Connect ADAM to your computer with serial interface. Make sure the Init/Normal switch of ADAM is Init for further setting. 2) Run ADAM Utility, and go to the specific COM port, and search. Then the device of ADAM 4017P will be shown. Figure 13: ADAM Utility Search 3) Change the Protocol as MODBUS from ADVENTECH, and update it. Make sure the BaudRate is 9600, and Address is 1. These values will align with the value in the Modbus RTU Client and IOS serial information Cisco and/or its affiliates. All rights reserved. Page 14 of 21

15 Figure 14: ADAM Utility Modbus Protocol Setting 4) Power off the ADAM 4017+, set Init/Normal switch as Normal, and power on it again. Now you will see the Modbus values accordingly. Figure 15: ADAM Utility Modbus Values Display 2015 Cisco and/or its affiliates. All rights reserved. Page 15 of 21

16 5.2 MODBUS MASTER SIMULATOR: MODBUS POLL You may use Modbus Poll to simulate your computer as the Modbus master. The tool is only for troubleshooting of Modbus protocol. You do not need to use it if everything is working well with ADAM and converters. Connect to your Modbus slave device such as ADAM with RS232 interface, and you may get all the Modbus values from ADAM ) Open the Modbus Poll, and go to Setup Read/Write Definition (F8). Set the Slave ID as 1 (the same value of ADAM address), put Address as 0 which means from the first channel of the Modbus slave, and put Quantity as 8 as ADAM has 8 channels at maximum. Figure 16: Modbus Poll Setup 2) Go to Connection Connect (F3), and set the relate values as following. Put the Serial interface with the specific COM you connects, set it as None Parity, and set Mode as RTU. Figure 17: Modbus Poll Connection 2015 Cisco and/or its affiliates. All rights reserved. Page 16 of 21

17 3) And then you will see the Modbus values fetching from ADAM You may set the values as Unsigned in the menu of Display. Figure 18: Modbus Poll Value Display 5.3 MODBUS SLAVE SIMULATOR: MODBUS SLAVE You may use Modbus Slave to simulate your computer as the Modbus slave. The tool is only for troubleshooting of Modbus protocol. You do not need to use it if everything is working well with C819 IOx and converters. Connect to the C819 with RS232 interface, and the C819 IOx Modbus RTU Client application may get all the Modbus values from the Modbus Slave of your computer. 1) Open the Modbus Poll, and go to Setup Slave Definition (F8). Set the Slave ID as 1 (the same value of the slave ID in your Modbus RTU client application), put Address as 0 which means from the first channel of the Modbus master, and put Quantity as Cisco and/or its affiliates. All rights reserved. Page 17 of 21

18 Figure 19: Modbus Slave Setup 2) Go to Connection Connect (F3), and set the relate values as following. Put the Serial interface with the specific COM you connects, set it as None Parity, and set Mode as RTU. Figure 20: Modbus Slave Connection 3) And set the related values in the table especially for the first value which will be fetched in IOx application. You may set the values as Unsigned in the menu of Display. In C819, you can see the value is fetched from the Modbus Slave and show in the console. Figure 21: Modbus Slave Value Display 2015 Cisco and/or its affiliates. All rights reserved. Page 18 of 21

19 6. TROUBLESHOOTING 6.1 HARDWARE CONNECTION (1) You could not connect the DB9 ports between RS232-to-RS485 converter and DB9-to-DB25 converter. The fact is that both DB9 ports are Female. The solution is you need an additional DB9 Male-to-Male adapter (crossover). Based on the definition of DB9 DCF(Female) and DTM(Male), the DB9 Male-to-Male adapter must be crossover, not straight through. The reason is: pin2 of DB9 DCF(Female) is TXD, and pin3 is RXD. And for DB9 DTM(Male), the pin2 is RXD, and pin3 is TXD. So you must crossover connect the both pin2 and pin3 for example. (2) You happened to have no standard DC power supply. Figure 22: DB9 Pinouts Definition and Adapter If there is no standard DC Power Supply available, you may simple use a DC12V power adapter for ADAM Check the polarity information in the guide of the power adapter. Usually the inside polarity of the power jack is positive voltage (+), and outside is negative voltage (-). (3) When you power on ADAM 4017+, the ADAM Utility did not show the MODBUS value. ADAM is set to the protocol of ADVENTECH by default. In that case, it does not show the MODBUS value. Use ADAM Utility to set the protocol to MODBUS with the switch of Init, put the switch to Normal, power it on again, and then you will see the MODBUS value. 6.2 C819 IOX (4) You did not get the guide for how to operate C819 IOx and SDK. Here is the link for the useful documents: 819-IOx-SDK-Cookbook: IOx Local App Manager: (5) You could not access the ova application in C819 with virtual-service connect name xxxxxxapp console. Please check the below things Cisco and/or its affiliates. All rights reserved. Page 19 of 21

20 Signed in the C819 Local App Manager, and check whether the deployed application is started or not. If not, start it. Access the C819 console, and check the status of deployed application in IOS with the command of show virtual-service list. Access the C819 console, and check the configuration of IOS. And check whether the iox host and guest OS are reachable with the command of ping and ping MODBUS RTU CLIENT APPLICATION (6) How to get the debug or log information for better troubleshooting? You may get the debug or log information from C819 Guess OS and IOS. At code level of libmodbus library, you may set the debug flag as TRUE in modbus_set_debug(ctx, TRUE); of modbusrtuclient.c file. And then you will see all the debug information from Modbus library. In IOS, you may turn on "debug raw-socket tcp packet" before you start the program and capture "show run", "show int s0", "show raw-socket tcp sessions" outputs. In IOS, you may run show interfaces serial 0 to get the information of the input/output data over serial interface. (7) How to get the source codes of libmodbus and debug inside the library? You may download the source codes of libmodbus from Uncompress it and get all the source codes of libmodbus including src codes, test codes, and doc. Go to libmodbus \src, and you will find all the source codes of libmodbus. If you want to modify the source codes or add the related debug information, you may use these source codes for compiling instead of the previous shared objects of libmodbus.so. For the Makefile, you should include all the.c source files below and remove libmodbus.so library accordingly. Here is a tip. As the bin file was created and packaged in the ova application, and deployed to C819 IOx accordingly. If you need to modify the code, you need to package the ova for deployment for every time. To avoid this duplication work, you may create the bin file based on the C819 IOx SDK toolchain, put it in a temporary path of C819 Guest OS with wget, make it executable, and run it for further testing and debug. steve@ubuntu:~/iox_c/modbus-src$ ls -al total 192 drwxrwxr-x 2 steve steve 4096 Apr 20 11:43. drwxrwxr-x 10 steve steve 4096 Apr 24 14:40.. -rwxrwxr-x 1 steve steve 767 Apr 14 13:35 imgb_cb_script.sh -rw-rw-r-- 1 steve steve 1135 Apr 15 12:24 Makefile -rw-r--r-- 1 steve steve Apr 15 12:24 modbus.c -rw-r--r-- 1 steve steve 2636 Apr 15 12:24 modbus-data.c -rw-r--r-- 1 steve steve 7866 Apr 15 12:24 modbus.h -rw-r--r-- 1 steve steve 4179 Apr 15 12:24 modbus-private.h -rw-r--r-- 1 steve steve Apr 15 12:24 modbus-rtu.c -rw-rw-r-- 1 steve steve 2386 Apr 15 12:24 modbusrtuclient.c -rw-r--r-- 1 steve steve 1434 Apr 15 12:24 modbus-rtu.h -rw-r--r-- 1 steve steve 2402 Apr 15 12:24 modbus-rtu-private.h -rw-r--r-- 1 steve steve Apr 15 12:24 modbus-tcp.c -rw-r--r-- 1 steve steve 1825 Apr 15 12:24 modbus-tcp.h -rw-r--r-- 1 steve steve 1506 Apr 15 12:24 modbus-tcp-private.h -rw-r--r-- 1 steve steve 2031 Apr 15 12:24 modbus-version.h 2015 Cisco and/or its affiliates. All rights reserved. Page 20 of 21

21 (8) Got some error to compile the Modbus RTU client application. First of all, please check the error information of compiling. And you may also check the below things. All the included.h files should be put in the same folder with the file of modbusrtuclient.c. The shared object.so file should be put in the same folder with the file of modbusrtuclient.c, or put it in the folder of /opt/ciscoiox/cisco_iox_sdk-x86_64-v0.1/tools/toolchain/powerpc-linux-gnu/powerpc-linuxgnu/libc/lib which is available by powerpc-linux-gnu-gcc -L. As the modbus.h is not a system library, use modbus.h instead of <modbus.h> in the example file of modbusrtuclient.c. (9) Run /usr/bin/modbusrtuclient.bin /dev/vport0p2 and exit with error. You need to look at the error information. And you may also check the below. Check the example application with ls -al /usr/bin/, and make sure the application is available and executable. Check the shared objects modbus.so file. It should be located in /usr/lib of the Guest OS. [root@p1020rdb ~]# ls -al /usr/lib/libmodbus* lrwxrwxrwx 1 root root 18 Apr /usr/lib/libmodbus.so -> libmodbus.so lrwxrwxrwx 1 root root 18 Apr /usr/lib/libmodbus.so.5 -> libmodbus.so rwxr-xr-x 1 root root Apr /usr/lib/libmodbus.so (10) Could not get the temperature date and got error information of Failed to read registers ret -1 after running /usr/bin/modbusrtuclient.bin /dev/vport0p2. There are lots of reasons to cause this error. You may set the debug as TRUE to show the debug information for further troubleshooting. And meanwhile, you may also try to figure out the issue with below possibilities. Hardware connection problem: you may use Modbus Poll tool to get the related Modbus data with the connection to ADAM and RS485-to-RS233 converter. And you may use Modbus Slave to make PC as a Modbus slave device, and run the Modbus RTU Client application on C819 to get the Modbus data from PC Modbus Slave. The former action to make sure the TMP36, ADAM 4017+, RS485-to-RS232 converter, and the connection work well, and the latter to make sure C819 and Modbus RTU Client, Cisco 232 DCF cable, DB9-to-DB25 converter, and connection work well. Configuration problem: please make sure all the slave ID, baud rate and address are exactly same in both Modbus master and slave side Cisco and/or its affiliates. All rights reserved. Page 21 of 21