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Serial Modem Interface (PLM)

Serial Modem Interface (PLM)


Regular price $79.95
Regular price Sale price $79.95

Shipping & Returns


Shipping costs are calculated based on location and are available when checking out.

Orders placed with FedEx Intl Priority, FedEx 2 Day, or FedEx Overnight by 12pm PT (Monday-Friday, non-holiday) are expected to ship same day.  Orders placed after 12pm PT are expected to ship the following business day. All other orders are expected to ship within 2 business days

Customers shipping to Canada will be responsible for all duties and import fees which will be due upon receipt.

Returns & Exchanges

New Products

New items have a 30-day return window and are warrantied for 2 years from the purchase date.

Refurbished Products

Refurbished items are guaranteed to be in good working condition but may have physical imperfections and/or may not include original packaging and documentation. If the product fails to work, you may exchange it for like product within 30 days of receipt.

Clearance Products

Clearance items are sold as-is and do not carry a warranty.

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Customer Reviews

Based on 9 reviews
Chris N. (Houston, US)
Replacement PLM resolved the issue

I am hopeful that the new PLM design last longer than previous versions

Joseph B. (River Edge, US)
New PLM Purchase

My PLM was acting up. Lights/receptacles were intermittently not turning off & on as scheduled. Replaced PLM and all is good again.

Morris F. (Sequim, US)
New PLM with existing UD Isy994i controller.

When I replaced a defective PLM that was working with a UD Isy994i everything worked well except the wireless motion sensors. I put each in set mode (1 at a time) but they would never link. I read and followed several blogs I found and none of them solved the problem. I then verified I had a good current backup. In the Isy994i device list I deleted one of the motion detectors. Then I tried to add it back as a new device. It still did not work. I then restored the Isy994i program. The link performed as it should after that. I did this for each MS that I had. Not sure why this worked, but it did. I submit this in hopes of helping someone else. It can always be a problem interfacing products from two companies.

Scott T. (Colorado Springs, US)
Shipped quickly and packed securely.

This is a backup to an existing interface. Have not installed yet. Run Homeseer on Linux. House has 80 plus Insteon devices, with Google Assistant integration for voice control.

Jeff H.
Absolute ****

Ship products that don't work. Replaced 2 in 4 years. Absolute garbage.

Hi Jeff, we're very sorry to hear that you've had a bad experience with the Insteon PLMs. Was the failure from your recent purchase in July? If so, we would very much like to get more details from you and review the failed unit since there have been component improvements in the newer units we are selling.

If this review is for a unit purchased before the new owners took over in June '22, we would very much appreciate if you would reconsider the low rating and give the replacement PLM some time to prove itself as an improvement over the older, more failure-prone units. If not, we completely understand.

Thank you.