Any relay experts here? Interface Probe 4-20ma output signal..

[AnnArborNate]

Hello folks!

I am getting ready to interface a Renishaw Probe and controller box to Acorn.

If I am reading the Renishaw manual for the P14 control box Manual link here-
https://www.renishaw.com/media/pdf/en/c ... 8eff9a.pdf (please note that this manual superceeded the Pi4 manual which is not availble. PI4 is MUCH simpler than the PI4-2. It does not appear to have one or more of the connectors (PICS connector noted)

It appears that when the Probe Interface 4, (PI4) outputs (in SSR Mode) a 4-20Ma signal. This output signal (4-20Ma) needs to be interfaced to acorn. Acorn wants "close to connect" connection of 24VDC onboard DC power on the Acorn. My understanding is that no signal except 24VDC (or its absence) (NO or NC, depending upon setting) may trigger inputs on the acorn, as in the following- Renishaw PI4 box outputting 4-20Ma when probe is triggered/ 4-20Ma signal goes to input signal on a relay and the relay then passes 24VDC to allow acorn to register the probe state.

I have been desperately searching for the following relay-
4-20Ma input circuit.
24 or higher DC output (this will trigger acorn)

If I am correct, this is the type of SSR relay I am going to need.

My probe is a Tp1s, and has been hooked up to the control box (PI4). Link to probe manual here-
Probe https://www.renishaw.com/media/pdf/en/0 ... c0da55.pdf

LSO-the Renishaw PI4 box has TTL output and SSR output. So if you believe I should switch the PI4 control box output to TTL, I would be most interested to hear about this.

I think I am sort of wrapping my head around how all this stuff can be interfaced. I have spent many hours over the past week trying to piece all of how this works together.

I have contacetd Opto-22, asking if they make such a relay and the engineer says they used to, but could not get me a PN.

If you have any input on this issue, I would appreciate you replying to the thread.

Thanks so much!

Nate.

[AnnArborNate]

Well, I may have just figured out that the SSR output is/are the connection point for the 24vdc (on acorn) to an input. Am I on the right track?

Its pretty hard to digest the Renishaw literature, with no background in electronics.

[eng199]

I think so. 4-20mA usually refers to analog interfaces. That is not something I would expect from a probe. With a quick skim of the documents, I don't see where you are getting that from. A solid state relay (SSR) could pull down an ACORN input, that is what needs to happen.

[AnnArborNate]

Yes, I believe you are correct. My understanding was the probe interface unit interfaced WITH an SSR. It does not. It interfaces THROUGH ITS OWN onboard SSR.

Just now, I managed to get the probe/interface box SSR output connections to connect Input 1 to Common on the acorn board. This works, I can change states in Acorn input 1 if I have ALT-I diagnostic up and have input 1 assigned to 4th axis limit switch (for testing)

So... not only am i ignorant, but when i try and learn sometimes I teach myself wrong.

Thanks for the reply. Thanks everyone for reading.

[AnnArborNate]

Probe now operational.

Also got ProbeApp V3

Swissi's turn time on my order was super fast.

[cnckeith]

Probe now operational.

Also got ProbeApp V3

Swissi's turn time on my order was super fast.

great! thanks for reporting back,

if a probe trips in the woods does it really exist? love to see video.