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U8-RLY-EXT-BELR

8 Channel USB Reed Relay Board W/DC Power Terminal Block

 
$127.56
Enclosure image is an example for illustrative purposes only and may not be the exact part number of the product.
U8-RLY-EXT-BELR
Typically a 2-3 Day Production <10pcs
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Quantity 5+ 25+
Price $121.18 $114.80
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Features

8 channel USB relay board with SPST (Form A) reed relays for fast switching and high reliability, No minimum voltage or current for contact load, 200VDC/200VAC resistive 0.5A   Note reed relays are typically not designed for controlling inductive loads.

Designed for single board operation or multiple board operation by adding RS232 units to the output on the USB relay board. Up to 16 boards can be connected in a daisy chain configuration, with up to a total of 128 - 10 Amp relays under computer control, on one USB port.  See example below:

With DC Terminal Block power input - typically used when a regulated DC power supply with sufficient capability is already available where the unit will mount, or to daisy chain units on one power supply.  Requires a regulated voltage between 9-12VDC @ 1Amp per board.  Includes reverse voltage protection to prevent damage to the board if the power leads were installed backwards.

  • ASCII commands to control relays.
  • Easy hook up using USB cable.
  • Any software language that can write to the PC serial port can be used with this relay board, since the USB driver creates a virtual COM port.
  • 4800-38400 baud (default 9600 baud)
  • LED Indicators for relays included
  • Download the USB driver from the location at the bottom of this page.

Eight Channel Relay Instruction Manual (8_ch_USB_Relay_Board_Instruction_Manual.pdf, 239 Kb) [Download]

Application Note 115 - Compatibility information (app_note_115.pdf, 91 Kb) [Download]

Application Note 156 - Detailed board command information (app_note_156.pdf, 127 Kb) [Download]

Compatible Accessories & Components


 

The information below describes the power options, (this is the voltage that powers the board itself - not the voltage/current the relays can handle).

Choose the option that best suits your application.  Some options are available only on specific boards, and it depends on the type of control and the relay options for that board.

AC Wall Adapter - wall power supply that converts the AC voltage to DC to power the unit, the cable plugs into the unit with a DC power connector.

DC Terminal Block - Typically used when a regulated DC power supply with sufficient capability is already available where the unit will mount, or to power a daisy chained string of boards.  Includes reverse voltage protection to prevent damage to the board if the power leads were installed backwards.  Most of our boards will operate on 9-12VDC.

120V 50/60Hz - This has an on-board power supply that will operate directly off the 120VAC line voltage.  The line voltage connects to a three position terminal block on the board that is marked with L1 (Line 1 -typically black), N/L2 (Neutral wire - typically white) and GND (Electrical ground - typically green or bare).  Common practice is to add an inline fuse for safety.

240V 50/60Hz - This has an on-board power supply that will operate directly off the 240VAC line voltage.  The line voltage connects to a three position terminal block on the board that is marked with L1 (Line 1 -typically black), N/L2 (L2 - typically red, but could be another color) and GND (Electrical ground - typically green or bare).  Common practice is to add an inline fuse for safety.

Bus Power Option - This power option is only for USB boards with the Reed relays installed and specific I/O boards.  The board is powered by the USB port and must be a high power port or USB port from a powered hub with a 500mA output. 

Note: USB devices are also required to automatically enter ultra low-power suspend mode when the USB host is suspended, and this may turn off the power to the board and all relays will turn off that were active.  Nevertheless, many USB host interfaces do not cut off the power supply to USB devices when they are suspended, it depends on the host controller.  If this is a problem for your application use the USB boards that are powered by an AC adapter or DC terminal block power versions - these will not turn off the relays once set by a command (unless the power is disconnected from the board).

Daisy Chain Operation

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.  Most 8 channel boards have an RS-232 output that is used to connect additional units using only one control port. 

Up to 15 additional relay boards may be connected to the first unit - for a total of 128 relays under the control of one port.  Each board has an individual hardware address that is set on each unit by a DIP switch.  This allows control of one unit that will respond to it's address without affecting the other units on the daisy chain.  All the units are hardware connected - so each unit receives the command sent to the first board almost instantly.

The first unit connected to the PC or embedded controller can be any of the control methods available.    However each additional board connected to the daisy chain are RS-232 units, as shown in the drawing below: The RS-232 units may be up to 50 feet or more between units.

In addition, if only one or two more relays are required for your application, a 1 or 2 channel unit may be connected as the last board on the daisy chain to add the extra relays or if you need to add relays and I/O and a couple ISO ports to your application.  

1 & 2 channel units are typically connected to only one control method, however one 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.

Daisychain configurations examples