Newbie RS232 communication

[WTE]

Before I explain the “problem” first a bit of background. I’m totally new to the Unitronics products but It seems to be a very usefull product range.

I have downloaded Visilogic and played with it a bit. Programming the instructions and functions doesn’t seem to be a problem. I have programming experience so I think I will manage that.

The major problem for me is the RS232 data communication with an external data acquisition system. I have the protocol of the unit but I don’t know how I can implement it in the Visilogic software to use it in my program.

I already have tried the communication init function and the FB protocol configuration but it’s not clear to me how I need to configure them. I’m not even sure that it is the right way to do it! I hope someone here can help me out.

The communication protocol is as below:

Communication protocol:

· Send out STX to activate a 12-channel measurement and get the response in the following structure:

· The first six ASCII characters contain the data from the first channel in the format:

Sign, H, T, O, D, Tab (sign, hundreds, tens, ones, first decimal, tab)<br style=""> <br style="">

· The second six ASCII characters contain the data from the second channel in the format:

Sign, H, T, O, D, Tab

.

.

· The twelfth six ASCII characters contain the data from the twelfth channel in the format:

Sign, H, T, O, D, EOT

Sign, Hundreds, Tens, Ones, Decimal refer to mV

Example: 2D, 37, 34, 30, 38, 09 means -740.8 mV of the first channel

I need decimal values as a parameter in the software so I can use them in calculations. Anyone which can help me with it?

Thanks in advance.