[Rock-dev] modbus library

[Martin Zenzes]

Hi,

looks like your code in ".../rock/install/lib/libbase_modbus.so" calls 
functions not present in the "/usr/lib/x86_64-linux-gnu/libmodbus.so".

You can use "apt-cache policy libmodbus" to check which versions of 
libmodbus are available, look up its documentation and adopt your api 
accordingly. You can also use "objdump" on both to looks whats actually 
there. Maybe cmake picks up a wrong "libmodbus.so" prior to linking to 
the installed one, here the "LD_DEBUG" environment variable comes in handy.

Having an english locale will results in english-language error 
messages, which are verbatim google search phrases. At least from time 
to  time ,-)

Hope something of this might help. Good luck ;-)
     Martin

On 04/27/2015 04:17 PM, fahrlich wrote:
> Hi
>
> i wrote  a modbus driver  that depends on linux-modbus library .
>
> The driver is called base_modbus  and  i added  a FindModbus.cmake file
> to the project
> and  following lines to the  CMakeList.txt in the src folder:
>
>      set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
> "${CMAKE_SOURCE_DIR}/cmake/Modules/")
>      rock_find_cmake(modbus)
>      include_directories(${modbus})
>
> So far , this works fine .
>
> Then i wrote another driver, called irdh_bender, that inherits from
> base_modbus.
> I did the same stuff  as described above: put the findModbus.cmake
> script into the the project folder and
> adapted the CMakeLists.txt
>
> This works fine, too
>
> Then i wrote a task, to run the irdh_bender lib. Again, i put the
> findmodbus.cmake file into project folder.
> Into CmakeLists.txt i added:
>
>
>      list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
>      message(STATUS "  cmake module path : ${CMAKE_MODULE_PATH}")
>
>      FIND_PACKAGE(Modbus REQUIRED)
>      list(APPEND EXTRA_LIBS modbus)
>     
>      include_directories(${MODBUS_INCLUDE_DIR})
>      message(STATUS "cmake module path : ${MODBUS_INCLUDE_DIR}")
>
>
>
> But if i run amake  i get following linking  error
>
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_new_tcp_pi'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_read_input_registers'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_flush'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_close'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_set_debug'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_free'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_connect'
> /home/fahrlich/code/rock/install/lib/libbase_modbus.so: Nicht
> definierter Verweis auf `modbus_strerror'
>
>
>
> But in rock/install/log/drivers/orogen/irdh_bender-configure.log ui can
> see that the lib was found :
>
>
>   cmake module path :
> /home/fahrlich/code/rock/drivers/orogen/irdh_bender/.orogen/config;/home/fahrlich/code/rock/drivers/orogen/irdh_bender
> -- Found libmodbus: /usr/lib/x86_64-linux-gnu/libmodbus.so
> -- Found modbus include Dir: /usr/include/modbus
>
>
> How can i fix this ?
>
> thanks
> Frauke
> _______________________________________________
> Rock-dev mailing list
> Rock-dev at dfki.de
> http://www.dfki.de/mailman/cgi-bin/listinfo/rock-dev

-- 
M.Sc. Martin Zenzes
Space Robotics

Hauptgeschäftsstelle Standort Bremen:
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E-Mail: martin.zenzes at dfki.de

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