rtiddsgen Request-Reply C++

Hi Timothy,

RTI Connext DDS includes a C++ example on how to use Request-Reply that includes a Makefile for armv6vfphLinux3.xgcc4.7.2 (i.e., the platform that runs on the Raspberry Pi). If you are using RTI Connext DDS 5.2.0, you should be able to find the example under ~/rti_workspace/5.2.0/examples/connext_dds/c++/hello_world_request_reply. To build the example from the example directory run:

cd ~/rti_workspace/5.2.0/examples/connext_dds/c++/hello_world_request_reply
export NDDSHOME=/path/to/your/installation/rti_connext_dds-5.2.0
make -f make/Makefile.armv6vfphLinux3.xgcc4.7.2

Note that you will need to have the  arm-linux-gnueabihf-g++ cross compiler in your path.

Alternatively, you can use rtiddsgen to create an example and tweak the example code and the makefile to build your Request-Reply application. That is, first create an example with the following command:

rtiddsgen -language C++ -example armv6vfphLinux3.xgcc4.7.2 Hello.idl

And then tweak the publisher and subscriber applications to behave as a Requester and a Replier like in the example.

For more information on how to use the Request/Reply API, check out this section of the RTI Connext DDS User's manual.

Let me know if this answers your question,
Fernando.

Hi Timothy,

Rtiddsgen does not include the library that contains the symbols for the Request/Reply API. Please, make sure that you include librticonnextmsgcppz in the autogenerated makefile:

LIBS = -L$(NDDSHOME)/lib/$(TARGET_ARCH) -lrticonnextmsgcppz -lnddscppz -lnddscz -lnddscorez $(SYSLIBS)

Let me know if this fixes your issue. If it does not, please share your makefile and I will help you debug what may be missing.

Thanks,
Fernando.

Hi Timothy,

Support for Request/Reply on Raspberry Pi was added in 5.1.0. The 5.0.0 libraries are part of an experimental port that was released only in this website, which only included the core libraries. Can you upgrade to 5.2.0 or 5.1.0 at least on the Raspberry Pi?

Thanks,
Fernando.

Hello,

The libraries should be the same as for Linux. RaspberryPi is a Linux larget, only it is an ARM rather than Intel architecture. But that does not affect the library names for example the dynamic non-debug libraries are  librticonnextmsgcpp.so  and   librticonnextmsgc.so. . For static it would be  librticonnextmsgcppz.a and  librticonnextmsgcz.a.

Perhaps you did not download the right target package? You need the Connext Pro targets. I think for the RaspberryPi that would be

rti_connext_dds-5.2.0-pro-target-armv6vfphLinux3.xgcc4.7.2.rtipkg

Note that the "basic" target package does not include the libraries needed for request/reply.

Gerardo

The pro libraries are in the customer support portal (https://support.rti.com/). You need to log in. I assume this is where you are downloading the 5.2 "basic" libraries for Arm as well... Is this right?

If after you log in to the portal you do not see the PRO package in your downnloads page it may be that you have not been enabled to access them? If that is the case you should send email to support@rti.com and request to have this download enabled.  Your affiliation says RPI so I assume you have an academic/research license in which case you are qualified to have the PRO bundles...

Thank you for the positve comments on the RaspberryPi HOWTO.  We will need to find some time to update it following your recommendation given the populatity. It is by far the HOWTO that has the most views :)

Gerardo