View Full Version : CSMIO/IP-M - wiring sanity check needed

15-10-2019, 12:04 AM
Hi all,

I'm currently rebuilding my old CNC controller with a shiny "new" enclosure and using the CSMIO/IP-M as the core (with MACH4 replacing MACH3).

From diagrams in the manual/cs-labs web site, as well as JAZZCNC's diagrams in other threads, I see that for e-stop and sensors the circuit for those takes both a 24v +ve from the PSU through the e-stop switch to a (+) input and then the other side takes a -ve from the PSU to the corresponding (-) input i.e. pins 1 and 14 for pair 0.

Question is, on my previous controller board there was just a plain circuit for the e-stop with 5v and 0v terminals and the e-stop switch in between, so why does the PSU feed need to be in the circuit for the e-stop on the CSMIO/IP-M, given that the PSU is powering the controller in the first place via its power connector?

Same goes for a ruby tipped probe or z height plate circuit, which I will also need to wire in a similar manner if I am reading the literature correctly.

Just checking before the first power up this week(end) and hopefully avoid any magic smoke if I have misinterpreted something.

Also if I decided to go with a 4PDT relay option, which version out of the options in the link below, would I need (I'm currently assuming the 220V AC one if I'm using it to cut the feed to the stepper's transformer)?


15-10-2019, 12:22 AM
Simple answer is that the CSMIO is designed for more sophisticated machines than a typical home-built router. Doing it this way means that you could use entirely separate power supplies for the CSMIO itself and for the external switch inputs. You probably don't want to, but you could. I use a CSMIO/IP-M myself partly because it means that you can use 24V external switching which is pretty much an industry standard and is much more resistant to external noise and false triggering. For example, I run limit switch, stepper motor, and VFD cables through the same cable chain and have never had a problem.

I have had and still do have CSMIO-related problems but I think that this is entirely due to the somewhat flaky interface between Mach3 and the CSMIO plugin which has needed a bit of care to make work at all reliably. No experience with Mach4, though.

15-10-2019, 02:31 PM
Thanks Neale

Sounds like using the 24V PSU feeds is OK then and I won't get a whiff of magic smoke :)

I guess another question is whether the 24V used is safe enough to use with the probe and/or tool height touch plate given it will be going through the spindle/tool (and me if I'm holding the plate onto the workpiece/bed)?

15-10-2019, 02:53 PM
No problem - that's what I use. Haven't had a shock off it yet! I use a movable touchplate in conjunction with a fixed plate set into the bed which makes tool-changing in the middle of a job much easier. It's a bit fussy about which version of Mach3 you use but not sure about Mach4.

Remember (if you haven't spotted it already) that the CSMIO has custom firmware in it for probing, and the best way to use a touchplate or probe is to use this via the CSMIO-specific functions. I wrote my own macros based on various examples available online designed for normal Mach3 but with modifications to use the CSMIO features, but again not sure about Mach4. When I built my machine Mach4 was still very flaky so I stuck to Mach3 and now it's all working, I'm not going to change!

15-10-2019, 03:09 PM
Neale's answer pretty much says it all regards the difference between Ip-M and your old controller. But the main reason you have to provide power to the Inputs and outputs is for isolation and cross interference. It also gives more flexabilty to what sensors can be used IE: Pnp Npn etc

Using 24V for probe etc is fine.

Regards the Relay your better with 24Vdc coil not 220Vac. The contact rating will depend on what your controlling. Just take note that if your controlling DC voltage the contact rating for DC will be lot lower than AC rating. If your thinking to control Transformer then your better using a Contactor not a relay as it can handle higher DC loads.

If go for contactor you still want one with 24Vdc coil.

15-10-2019, 11:03 PM
Thanks guys, it will be good to get cutting something again.

For the relay Dean, I was looking at the diagram you did in another thread with the transformer cut and the RST/DCM circuit to the VFD - this one:26548

This looked to be very close to where I hope to end up, but with my existing ruby probe and touch plate added in.

I don't suppose you have a link to the contactor/coil unit I would need?

27-10-2019, 07:46 PM
Quick update and a follow on question (probably worth a new thread also).

Just to confirm the 24V wiring solution appears to be functioning correctly on both the e-stop and probe circuits and I can see them functioning/triggered in Mach4 - thanks guys for the reassurance :applouse:

For the follow on question I haven't got movement yet and I think it has something to do with the PM752 drivers I am using and a lack of Enable connections on those, or it is possibly something in Mach4 related to "Enable" that I am missing, but I'll start a new thread for that...