Connecting Emerson Wireless Transmitter to HMI

A week ago my friend called me and want me to do a test connecting emerson wireless transmitter to wonderware HMI. i agree because from my view wireless is only the media and the protocol is still using the same common known protocol, modbus.

so, the design is like this :

Wireless Gateway Testing Diagram

wireless transmitter will communicate with Gateway using wireless protocol (not pure 802.11 wireless but encapsulated with Hart Protocol). and from wireless gateway i use cat 6 UTP cables to connect with HMI (using common switch/hub)

Then we agree to install all the testing stuff. First we have to find a 24vdc as power source. i'm not ready with that before. although i have 3 different mini PLC, but the power source is already installed in the cabinet so it was difficult to use existing power source.

first, we have to make sure the transmitter can communicate with wireless gateway. we can monitor it using the browser and put wireless gateway's IP for the address. the result is wireless transmitter can communicate with the wireless gateway.

i use wonderware 10.5 and install DASMBTCP for the I/O driver. add 1 Modbus PLC as the RTU and put Wireless Gateway IP Address for the address.
try to get 1 tag from the wireless transmitter and the result is....
fail :)
it must be something wrong with the setting.

first, because DASMBTCP communicate using old modbus protocol which is using port 502, so i have to enable port 502 at the wireless gateway setting. and also submit each tag from the transmitter to register. here we can use register 40001 until 4xxxx.

second, at the DASMBTCP I/O Module, we have to define how many digit for the register. the default number is 6. because i'm using 40001 for the register that holding tag from the transmitter, i have to put 5 for the digit.

and after some modification... voila... the wireless transmitter value can monitored using wonderware HMI. you can set the refresh time to maximize the update rate from the device and make real time monitoring for the operator.