***updated model 25/02/2020 launched - features red & yellow LEDs to indicate transmission & reception of data, 0V & power disconnect to allow complete isolation of the relays. Data sheet update and specifications update on the way soon. The board remains the same size as the previous model. Please contact us if you need more details***

This low cost, general purpose, USB powered board has  4 opto-isolated relays and four general purpose digital I/O channels.

The relays are high sensitivity (gold contact) signal relays (30VDC@1A).  Access to all relay contacts and the 4 DIO channels is via fixed screw terminal block connectors  along the edge of the card. 

Suitable for a wide range of control and signal switching purposes, it also offers screw terminal access to the USB power connections for possible onward powering/use in your target system .  The card comes with +5V & relay channel LED status indicators. 

Nylon feet are fitted in each corner which will take self tapping screws.  They can easily be removed to allow the cards to be mounted on pillars or stacked.  There is also a perspex cover available which offers general protection of the card and prevents accidental contact with any of the relay contacts or screw terminal connections.  In addition, there is a DIN rail mount/cover option available.

These are industry standard relay boards and products.  High quality, for professional electronic  automation,  connectivity, and control.

Easydaq products are used in research and education, security, industrial applications, power and energy management,  motor and device  control. There are uses across various industries, including  maritime , rail,  automotive, automation, measuring and calibration, agriculture , medical, sanitation, light and power solutions, fire protection, defence, security, and many more.

Download datasheet

Operational Parameters
Control Interface USB
Relay Channels 4
Digital input channels 4
Relay Type S
Digital output channels 4
Opto-isolated Y


  • Product Code: USB4SRMx
  • Availability: In Stock
  • £52.00

  • 10 or more £46.80
  • 25 or more £45.50
  • 50 or more £44.50
  • 100 or more £43.80

Related Products



CoverUSB4MxDIN A Perspex cover for the USB4Mx which offers general protection of the card.  ..




A Perspex cover for the USB4Mx which offers general protection of the card .Should these be purch..




3 metre type A/B USB cable, suitable for use with any of our USB card product range..




Recommended for use across relay contacts in 120/240VAC mains switching applications.  (Minimis..


Tags: USB, 4 channel signal relay board,