MTS Temposonic Probe

I've a strange problem, hope one of you can help. Thanks in advance. I searched the forum and did not see anything on this.

These tempos and Moog servo valves are connected to QB modules in a PLC5.

We are using MTS LHSR 12" tempo's, they are no longer made.
The replacement probes are MTS GHT probes. Six probes have been replace with no problem. There are four cylinders in which the GHT probe will not work...get a neg 1 for feedback. Put a LHSR probe back in everythings fine. I've checked all wiring for differences, there are none. I've checked the configuration files(integer data table) of the ones that work against the ones that won't, again I don't see any differences.

Any suggestions?

My favorite topic, not

Have you tried removing the rod and moving a magnet up and down the rod? It is possible that the position range where the magnet can be detected has changed. If your magnet is not at either extreme try moving it toward the center of the actuator stroke by using some sort of open loop command.

Make sure the number of recirculations and whether the rods is start/stop or PWM is set right. QBs like 2 recirculations and PWM mode. I am not sure they can be set up differently.

Get a scope.

Yes Peter,

I have a module that connects to software on my laptop. When the magnet moves from probe head to end the value increases from 0-12 inches. There are no dead spots. Whathas me confused is that only some don't work, I would think all would or none would.

There are 2 recirculations. No plc changes were made when swapping probes

Got it.

Tempos

We have had some interesting problems also. It is almost like the feedback is going out of range. I would swap out a cyl from a working axis and exchange it with a nonworking axis cyl. If it works, the wiring, configuration etc is good. If it does not then there is a wiring or configuration problem. You could also remove the probe and watch the QB Feedback and pass a magnet up and down the probe shaft. See if you can get the same results. ( neg 1). Check the software configuration on each probe, your config should be 2 Recircs, External, PWM. I dont think this is the problem, but check each out. Try also replacing one of the four cyl with a new one. We ended up replacing 3 out of 8 Cyl on one machine when we changed to G series probes. The cyl are working fine, just not with this probe.

Bruce99 said:

It is almost like the feedback is going out of range.

Click to expand...

Yes, this is a common problem. Our controllers have a error bit for these kinds of problems. The problem we have is that we get the tech support call because our product reported the error. You don't know how many times I have told customers that we don't cause the problem, we just report them. Some how who ever reports the error must fix it even though there is nothing wrong with the motion controller.

I am very surprised at the reluctance to use an oscilloscope.
We like to use scopes. They make make short work out of MDT problems. Unfortunately we haven't found a way to use a scope with goto meeting.

There are 2 15vdc powersupplys, -15v& +15v tied together supplying a moog servo valve with 30v. The tempo was looking for a +15v supply. Some of them had the -15v connected also. The old L series tempo apparently wasn't affected, but the G series tempo would output a neg value regardless of the magnet position. Removing the neg voltage fixed the problem.

Thanks for your response.