8 channel wireless relay problem

I just installed wireles relays on 8 machines. Everything worked perfectly for three weeks. They are hooked in a PLC and HMI monitors the status. Its a simple, machine running, relay on. Two of the machines are not powered up yet but this morning they are showing as “running” the relays are on. This makes the system usless unless I can find that signeled the relays to “on” Any ideas?

What product are you using? We sell a lot of “wireless relay” products.

MirW Contact Closure Multi-Point to Point 8-Channel 2-Mile Range - 5 Amp SPDT Relays
900MHz (North America) Long-Range Wireless Mesh XBee-Pro® Communications Module

Do non of the transmitters work? You should be able to manually trigger inputs on the transmitter boards and corresponding relays on the receiver should turn on and off. Generally those devices do not stop functioning unless something is physically damaged.

They are working properly, tested. To be clear, we have installed and tested them. They work properly. We are in the process of bringing the machines into production, (they are simply changing patterns, they are not new, just adding these to them when they were down for the change) With out even powering them up, something turned two channels on, two relays came in on the reciever indicating running machines on the line. Really scratching my head in this one.

So, to turn them off, I powered up the equipment. Manually pressed the Run Relay, then released the relay and they turned off as they were supposed to.
The problem, How and why did they turn on with no power to the remote relay? This literally destroys the functionality of the system. The production numbers are off by the amount of time the relays were mistakenly were on.
I need to understand what else can turn these relays on the receiver on.

That is extremely odd. You might make sure the relay board is properly earth grounded. It almost sounds like interference coming into the board causing the relay’s to be inadvertently turned on. I have only seen this when the relay board was mounted near a very high power radio device or when it was mounted near really noisy electrical devices such as a large AC motor.

It is very odd, The reciever is in my office, We are using a HMI that is connected to our intranet and wifi to view the machine status from our phones and computers

I would keep an eye on it to make sure there are no more false triggers in the near future. Hard to say what could have possibly caused that. It would have required a very specific wireless transmission to come through to cause a false trigger.