Made in USA Flag All board products Proudly made in USA!

Manufacturer of computer controlled relay, I/O and custom boards for commercial and industrial applications.

Please Note: Pencom will be closed from September 12th thru September 23 - we will re-open on September 26

** Please note supply chain shortage update 09-07-2022 -  a limited supply of the backordered parts will be arriving around September 28th for the USB boards - more parts are on order:   We have many backordered boards that will be produced first - notifications will go out to customers to verify the orders are still valid.

There will be production delays due the volume of the backorders

Due to the supply chain shortages we have been having a difficult time obtaining parts to produce our products.  Some of our parts have been on order for 12 months  Some parts are being received for certain products and we will do our best to fulfill what we can.

In addition we have been experiencing problems with our email system and many emails were never received on the following accounts our and, this has been happening for some time and we were unaware since it is happening sporadically. 

We have created two new accounts to use until we can determine the problems we are having with our system and please use these emails to contact us.

Other email address have been the same problems and we will work to correct these too.

Product filters Product filters

Relay Boards With I/O

Computer controlled relay boards, with additional input/output ports.

Relay boards with relays outputs in SPST, SPDT contact configurations, and additional logic level input/output ports to read a logic signal or output a logic level. 

Some versions also have opto-isolated inputs on the boards that can handle higher voltage typically up to 28VDC (or more with external components)

8 Channel relay boards have the capability to daisy chain units in a string connected to one control method (RS-232, USB, etc.) on the PC or embedded controller.  The first unit connected to the PC can be any of the control methods, and the units connected to the daisy chain are RS-232 units, as shown below.  The RS-232 units may be 50 feet minimum between units.

Most 1 & 2 channel units are typically connected to only one control method, however one (1 or 2) channel RS-232 board may be the last board on the daisy chain if only a couple extra relays are needed to save cost.  This board would be address "A" as this is set in firmware, and the other boards would need to be set to "B" through "P", so each board may be accessed separately.


  • Industrial control applications
  • Automatic test equipment (ATE)
  • Process control systems
  • Power switching applications