Features red & yellow LEDs to indicate transmission & reception of data, 0V & power disconnect to allow complete isolation of the relays. 

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, security, and many more.

You can order any of our boards with customisations or without connectors fitted - contact us for prices

Download datasheet

EasyDAQ is primarily a business-to business seller, supplying products around the world, therefore advertised prices exclude VAT. Customers in the UK and Northern Ireland will be charged VAT  at checkout. 

Operational Parameters
Manufacturer EASYDAQ
Control Interface USB
Relay coil voltage 5V
Relay Channels 4
Relay contact current 1A
Digital input channels 4
Relay Type SIGNAL
Digital output channels 4
Opto-isolated YES


  • Product Code:USB4SRMx
  • Availability:In Stock
  • £67.11

  • 10 or more £41.60
  • 25 or more £36.92
  • 50 or more £34.63
  • 100 or more £32.55
  • 250 or more £30.42
  • 500 or more £28.18

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Tags: SIGNAL, USB, 4-relay, relay, board, USB4SRMx, EasyDAQ, UK, RoHS, CE, 3TG,