CoppeliaSim forums

Posted: **22 Mar 2022, 18:29**

I'm using a custom ros service data:

rossrv show beginner_tutorials/AddTwoInts
int64 a
int64 b
---
int64 sum

I'm able to make server work perfectly fine (tested with terminal):

Code: Select all

function sysCall_init()
    -- do some initialization here
    sev = simROS.advertiseService('/add_server', 'beginner_tutorials/AddTwoInts', 'add_number')
end
function sysCall_cleanup()
    -- do some clean-up here
    simROS.shutdownServiceServer(sev)
end
function add_number(req)
    ans = req.a + req.b
    print(ans)
    p={sum=ans}
    return p
end

But problem client is not working. As soon as I hit play entire simulation just get stuck

Code: Select all

function sysCall_init()
    -- do some initialization here
    client = simROS.serviceClient('/add_server', 'beginner_tutorials/AddTwoInts')
    print(client)
    if client then
     values = {a=1,b=5}
     result=simROS.call(client, values)
    end
end

As soon as I hit play entire simulation just get stuck. after I do ctrl+c everything stop and I get error in the terminal.

7: failed to call service beginner_tutorials/AddTwoInts (in function 'simROS.call@simExtROS')
stack traceback:
[C]: in function 'simROS.call'
[string "Dummy@childScript"]:7: in function 'sysCall_init'
[Dummy@childScript:error] 22: non-existent object handle (in function 'simROS.shutdownServiceServer@simExtROS')
stack traceback:
[C]: in function 'simROS.shutdownServiceServer'
[string "Dummy@childScript"]:22: in function 'sysCall_cleanup'

I'm not sure how to write the "values" in simROS.call(). Let me know what is the write way to make ros client.
Thanks in advance !!!

Posted: **31 Mar 2022, 10:56**

Yes, that is the correct way of calling a ROS service from CoppeliaSim. If calling service fails maybe the service name or type are not correct.
Check with rosservice list etc...

I tested with the rospy_tutorials package, and calling the AddTwoInts service works as expected.

Code: Select all

function sysCall_init()
    client=simROS.serviceClient('/add_two_ints','rospy_tutorials/AddTwoInts')
    if client then print(simROS.call(client,{a=1,b=2})) end
end

function sysCall_cleanup()
    if client then simROS.shutdownServiceClient(client) end
end

prints:

Code: Select all

{
    sum=3,
}

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ros client not working

ros client not working

Re: ros client not working