OpenAPC Modbus TCP communication issues

[Pradeep Dissanayake]

Hi I am trying to establish comms between Mango M2M (modbus TCP master)
and OpenAPC (modbus TCP Salve). but so far have no any luck.
I tried to tracking the data using modscan I found that :
1) the Transaction Identifier is always 0000 (not replicating the master)
2) the Message Length is 2 bytes smaller than in the actual response value.
could this have happen due to data string being 32bit ???

However what is your recommendation
can you please please help me

best regards
PD