TCP Message Tag manipulation

[Craighunter1986]

Hi,

I am connecting a Mettler Toledo Scale with an RS232 via a Serial to Ethernet device. I have then connected the device to Ignition using the TCP driver and started to poll the Message tag for the weight being displayed. This works but I am receiving a string with characters that I don’t require. I am only really looking for the numbers and not the text.

example:

Whats I am getting - S S 31.1g

What I would like - 31.1

I have looked at transform I but couldn’t see anyway to do this, any advice?

Thanks

[wking]

You can most likely edit what the nature of the message is at device level through print settings. If that doesn’t work. You could get the expected output with a script. The S is maybe stable? This was my experience integrating Ohaus scales.

[Craighunter1986]

thanks Wking. the setting on the scales seem quiet basic and couldn't see any print settings to adjust.

After multiple searches I came across the below link and managed to create and expression tag based on the OPC tag. Not sure if it is the best solution, but it works!

Casting String to Integer with Expression

If I have an OPC tag that returns a string and I would like to convert it to an integer then what is the expression statement to do this? For example, if the strings look like any one of these: 0.0? 125.0? 99.5? I would like to convert them to the following float values 0.0 125.0 99.5 The ‘?’ is part of what the device returns. I used the replace function to remove the ‘?.’ I used the replace function to remove the ‘.’ and then cast it to integer and float but I get an evaluation error. …