Seam Tracking with TPSI and analog current clamp.

Hi guys,

i have a robot cell that uses a fronius TPS/I 500 in combination with a current clamp to do seam tracking (TAST).

this welder has the ability to output a digital seam tracking signal but it's not used as the robot controller does not support it.

we are having mixed results with seam tracking... and just feel its more finicky than it should be.

we are pulse welding 12-16mm mild steel.

i believe back in the fronius TPS days you had to use a specific synergic line (weld program) when using seam tracking.

(please see attached PDF screenshots)

I'm assuming it controlled the arc a little differently to allow for the current clamp to get a better signal.

does a new version of (P0555) exist for the new TPSI machines or are we just expected to use the digital signal?

cheers,

-william foster

i will try making a device to intercept the mod bus seam tracking signal and pass an analog signal to the robot controller...

Seam tracking working with converting the digital mod bus signal to analog...

i think it's working better.

lots of variables.

image shows taught vs welded path.

the welder is already sending a seam track signal to robot via modbus over ethernet.

the robot just is not setup up to do anything with it... as DX200 is not digital comarc compatible.

i put a computer between the robot and the welder.

it's running a program to "intercept" the modbus packets and read their value.

it then outputs via serial to the Arduino that outputs the value in analog to the robot.

after that it's just the same as regular comarc.

I'm not entirely sure of it's performance yet... i need to conduct more test welds.

i have a feeling its better.

Quote from hermann

There exist modbus TCP client software for Arduino f. e. https://github.com/goddland16/Modbus-TCP

I tried that first,

I don’t think you can make it work just by listening in on the traffic.

only worked when I sent it direct commands.

I think it’s to do with how Ethernet library works.