Low cost 2 channel serial relay board controlled through one of the RS232 serial ports, 10 Amp 250VAC/28VDC SPDT power/general purpose relays - with an on-board 120VAC 50/60Hz power transformer. (NO enclosure available).
Includes 9-pin RS232 to modular cable adapter & 7' Modular cable
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).