SOLVED:Using TCP binding and JS transformation to write ebus value

Hi I am trying to write values to the ebus through the ebusd daemon.
Through telnet I managed to write ot values with no probs:

lraspOH201:~ $ telnet 8888
Connected to
Escape character is '^]'.
write  -c wolfcwl LuftmengeStufe1 75

I setup following item:

Number CWLStep3VolW "LuftmengeStufe1  [%.0f m3" {tcp=">[CHANGED:]" }

And following sitemap entry too:

Setpoint item=CWLStep3VolW minValue=50 maxValue=250 step=5

I created a tranformation JS

(function(i) {
//    logInfo("WolfWrite", "write  -c wolfcwl LuftmengeStufe1 " + i)
    return "write  -c wolfcwl LuftmengeStufe1 " + i + "\n";

The things somehow are not working. I do not have any traces in the log that the transformation is called. neither the values are set
what am I doing wrong?
I guess logging is not possible there?

when I change the item:

Number CWLStep3VolW "LuftmengeStufe1  [%.0f m3" {tcp=">['JS(wolfWriteStep1.js)']" }

I get :

2017-07-06 12:52:09.915 [ERROR] [ing.tcp.AbstractSocketChannelBinding] - there is no channel that services [itemName=CWLStep3VolW, command=85.0]

at least one entry has to be made in the tcp.cfg.
that is, although there default values mentioned in the description