Remote contact closure monitoring for 26 devices into a PLC

A new client asked us to run shielded 18-2 cables from a contact closure on each of the 26 mold machines in a factory. Those cables terminate 250ft into a PLC enclosure with 26 pair contacts.

Which devices would you recommend. Hard wiring is the most time consuming and labor intensive, but the least amount of problems down the road, but expansion becomes a problem.

The contact closure tells the PLC that a part has been completed, so you will be getting 26 monitor events every 30 seconds or so.

The mold machines are typically in a pod configuration, I can probably connect 8 of them to a transmitter.

could I use a 32 unit receiver , then output those to the inputs on the PLC ?

Hi,

So just for clarity you have 26 total contacts that need to be wirelessly transferred to a single PLC.

These 26 contact closures could be wired in groups of ~8 to a single transmitter.

If the above is true, you could use this product: https://store.ncd.io/product/mirw-contact-closure-multi-point-to-point-32-channel-2-mile-range/. It operates in the 900MHz frequency range and can be tuned down to a shorter range to reduce interference on that band.

The transmitters are available under the Buy Now tab and you can order 3 8-channel transmitters and one 2-channel. We will map these at our facility to relays 1-26 on the receiver.

When the transmitter detects a contact closure it will tell the corresponding relay on the receiver to go the NO position which will close the contact into your PLC. When the contact closure is opened on the transmitter the corresponding relay on the receiver will revert to the NC which will open the contact on the PLC.

Let me know if I misunderstood your application or if you have any questions. I apologize for the delay, we’re playing catch up on support and pre-sales after the 4th.

I think this is exactly what I need… I currently have a FXR24X board of yours, with an FLL board. This sounds very similar.

Can you supply the link for the 8 channel transmitter, I could only find it in a package. I found this one, but it was USB and not XBEE https://store.ncd.io/product/8-channel-push-notification-contact-closure-input-over-usb/

1 when you talk about tuning the 900MHZ, is that using DIGIX-CTU and reducing from 250mw ?.
2. If I need to change mapping or add items, what software do I need to make that change ?.
3. Do you have pictures of what the steel enclosure looks like and does it include an external antenna ?

Thank you very much.

Mechanically they’re very similar. The transmitters are programmed at the factory to transmit specific relay control commands using the ProXR series command set which defers only slightly from the Fusion ProXR command set. You can program the transmitters with Base Station to send Fusion commands provided that you have a ZUSB module to communicate to the transmitter’s on-board chip.

The major downside is that the transmitter’s relay status LEDs won’t function as the Fusion series doesn’t respond in the same way as the MirW series and support on it would be more difficult as its a custom rig.

The push notification uses the same hardware, but its different firmware on-board.

If the above sounds acceptable to you I can activate the MirW transmitters to be sold separately.

  1. That is exactly right. You’ll need a USB Configuration Adapter to alter this in the field or we can alter this here on request.
  2. You would need Base Station and a USB module (ncd.io/start)
  3. Bad phone pictures. These are for a MirC Transmitter, but again same board, different firmware.

Perfect

so that I can be self sufficient in this, please make sure I have everything. I have an XCTU , we use the Xbees all of the time for another of our projects…

The cases look great

so for 1 32 channel receiver, and 4 8 channel transmitters, with cases and power adapters , 5 Amp

It looks to be about 1547, here is the cart code https://store.ncd.io/kc/7k34

I am not planning on using the attached picture, but I do have the ZUSB for programming. I would like to have the ability to have lights reflecting the status.

If this looks good , let me know and I can get this quoted.

Barry

This looks like all you’d need.

Just for clarity, XCTU is the software which connects to and configures devices like the USB Configuration adapter I mentioned earlier.

If you’re using XCTU with something other than our USB Configuration Adapter just make sure it has the XBee Socket so you can swap in an individual transmitter to pull its wireless network ID, pre-amble, and other network information. If you can send me a photo of the hardware you use with XCTU I can check this for you.

I took some pictures of the XBEE bin

![XCTU2|375x500]

Thanks for everything.

This part outlined in red should allow the wireless modules from the transmitter/receiver to be reprogrammed if anything goes down or if you want to change settings in the wireless for any reason.

I can’t guarantee it because I’ve never used that particular one, but its an XBee Socket pinout with a USB interface.

It should mount as a virtual serial port and allow XCTU to read and write settings.

Thank you for everything.

Barry

You’re welcome.

Let us know if you have any other questions.

I have a couple more questions after talking to the client.

They originally were going to put a device in the machine that converted 24V DC to a contact closure, could I change out the transmitter and save that item also.

He will give me 24V dc, two leads, we need to send the high state over, keep the relay on the other side open, and when it goes low, turn off the relay on the other side.

lastly, how many simultaneous relays will it allow to track, and what would be the delay, the normal 30 microseconds of transmission time ?

The PLC is going to measure interval of on to off, and off to on ?.

I found this, but I needed push, rather than user defined intervals ? https://store.ncd.io/product/long-range-iot-wireless-multi-channel-wet-contact-closure-transmitter/

Barry

“They originally were going to put a device in the machine that converted 24V DC to a contact closure, could I change out the transmitter and save that item also.”

Unfortunately not at this time with off the shelf hardware. The transmitters for this accept contact closures only.

“lastly, how many simultaneous relays will it allow to track, and what would be the delay, the normal 30 microseconds of transmission time ?”

All relays on the receiver can be active at the same time. Realistically each relay will update one at a time in this configuration. The delay is variable based on signal strength and the number of transmitters, but it can be up to 1 second on the delay.

“The PLC is going to measure interval of on to off, and off to on ?.”

Our boards don’t measure the intervals between the on and off states of the relays on the receiver, they simply transmit contact closures to a receiver to activate a relay.

“I found this, but I needed push, rather than user defined intervals ? https://store.ncd.io/product/long-range-iot-wireless-multi-channel-wet-contact-closure-transmitter/

That particular device is designed primarily for data aggregation to local and cloud storage. You could use this for device to device control, but it would necessitate firmware development on an embedded microprocessor platform such as ESP32 or Raspberry Pi on the Receiver.